dt-bindings: Add LM81 and DS1780 as trivial devices

The LM81 and DS1780 are close relatives of the ADM9240 and already
supported by the same driver. Document them as trivial devices.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20200923051637.30464-1-chris.packham@alliedtelesis.co.nzSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/trivial-devices.yaml

@@ -54,6 +54,8 @@ properties:
           - dallas,ds1682
             # Tiny Digital Thermometer and Thermostat
           - dallas,ds1775
+            # CPU Peripheral Monitor
+          - dallas,ds1780
             # CPU Supervisor with Nonvolatile Memory and Programmable I/O
           - dallas,ds4510
             # Digital Thermometer and Thermostat
@@ -296,6 +298,8 @@ properties:
           - national,lm75
             # Serial Interface ACPI-Compatible Microprocessor System Hardware Monitor
           - national,lm80
+            # Serial Interface ACPI-Compatible Microprocessor System Hardware Monitor
+          - national,lm81
             # Temperature sensor with integrated fan control
           - national,lm85
             # I2C ±0.33°C Accurate, 12-Bit + Sign Temperature Sensor and Thermal Window Comparator