Since 4.30 firmware exposes internal thermal sensor reading via admin
queue commands. Expose those readouts via hwmon API when supported.

Datasheet:

Get Sensor Reading Command (Opcode: 0x0632)

+--------------------+--------+--------------------+-------------------------+
| Name               | Bytes  | Value              |          Remarks        |
+--------------------+--------+--------------------+-------------------------+
| Flags              | 1-0    |                    |                         |
| Opcode             | 2-3    | 0x0632             | Command opcode          |
| Datalen            | 4-5    | 0                  | No external buffer.     |
| Return value       | 6-7    |                    | Return value.           |
| Cookie High        | 8-11   | Cookie             |                         |
| Cookie Low         | 12-15  | Cookie             |                         |
| Sensor             | 16     |                    | 0x00: Internal temp     |
|                    |        |                    | 0x01-0xFF: Reserved.    |
| Format             | 17     | Requested response | Only 0x00 is supported. |
|                    |        | format             | 0x01-0xFF: Reserved.    |
| Reserved           | 18-23  |                    |                         |
| Data Address high  | 24-27  | Response buffer    |                         |
|                    |        | address            |                         |
| Data Address low   | 28-31  | Response buffer    |                         |
|                    |        | address            |                         |
+--------------------+--------+--------------------+-------------------------+

Get Sensor Reading Response (Opcode: 0x0632)

+--------------------+--------+--------------------+-------------------------+
| Name               | Bytes  | Value              |          Remarks        |
+--------------------+--------+--------------------+-------------------------+
| Flags              | 1-0    |                    |                         |
| Opcode             | 2-3    | 0x0632             | Command opcode          |
| Datalen            | 4-5    | 0                  | No external buffer      |
| Return value       | 6-7    |                    | Return value.           |
|                    |        |                    | EINVAL: Invalid         |
|                    |        |                    | parameters              |
|                    |        |                    | ENOENT: Unsupported     |
|                    |        |                    | sensor                  |
|                    |        |                    | EIO: Sensor access      |
|                    |        |                    | error                   |
| Cookie High        | 8-11   | Cookie             |                         |
| Cookie Low         | 12-15  | Cookie             |                         |
| Sensor Reading     | 16-23  |                    | Format of the reading   |
|                    |        |                    | is dependent on request |
| Data Address high  | 24-27  | Response buffer    |                         |
|                    |        | address            |                         |
| Data Address low   | 28-31  | Response buffer    |                         |
|                    |        | address            |                         |
+--------------------+--------+--------------------+-------------------------+

Sensor Reading for Sensor 0x00 (Internal Chip Temperature):

+--------------------+--------+--------------------+-------------------------+
| Name               | Bytes  | Value              |          Remarks        |
+--------------------+--------+--------------------+-------------------------+
| Thermal Sensor     | 0      |                    | Reading in degrees      |
| reading            |        |                    | Celsius. Signed int8    |
| Warning High       | 1      |                    | Warning High threshold  |
| threshold          |        |                    | in degrees Celsius.     |
|                    |        |                    | Unsigned int8.          |
|                    |        |                    | 0xFF when unsupported   |
| Critical High      | 2      |                    | Critical High threshold |
| threshold          |        |                    | in degrees Celsius.     |
|                    |        |                    | Unsigned int8.          |
|                    |        |                    | 0xFF when unsupported   |
| Fatal High         | 3      |                    | Fatal High threshold    |
| threshold          |        |                    | in degrees Celsius.     |
|                    |        |                    | Unsigned int8.          |
|                    |        |                    | 0xFF when unsupported   |
| Reserved           | 4-7    |                    |                         |
+--------------------+--------+--------------------+-------------------------+

Driver provides current reading from HW as well as device specific
thresholds for thermal alarm (Warning, Critical, Fatal) events.

$ sensors

Output
=========================================================
ice-pci-b100
Adapter: PCI adapter
temp1:        +62.0°C  (high = +95.0°C, crit = +105.0°C)
                       (emerg = +115.0°C)

Tested on Intel Corporation Ethernet Controller E810-C for SFP
Co-developed-by: Marcin Domagala <marcinx.domagala@intel.com>
Signed-off-by: Marcin Domagala <marcinx.domagala@intel.com>
Co-developed-by: Eric Joyner <eric.joyner@intel.com>
Signed-off-by: Eric Joyner <eric.joyner@intel.com>
Reviewed-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Konrad Knitter <konrad.knitter@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>