docs: i2c: i2c-protocol: remove unused legend items

"Comm", "Count", "DataLow", "DataHigh" are not used in this section.
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Documentation/i2c/i2c-protocol.rst

@@ -15,11 +15,7 @@ Rd/Wr (1 bit)   Read/Write bit. Rd equals 1, Wr equals 0.
 A, NA (1 bit)   Acknowledge (ACK) and Not Acknowledge (NACK) bit
 Addr  (7 bits)  I2C 7 bit address. Note that this can be expanded to
                 get a 10 bit I2C address.
-Comm  (8 bits)  Command byte, a data byte which often selects a register on
-                the device.
-Data  (8 bits)  A plain data byte. Sometimes, I write DataLow, DataHigh
-                for 16 bit data.
-Count (8 bits)  A data byte containing the length of a block operation.
+Data  (8 bits)  A plain data byte.
 
 [..]            Data sent by I2C device, as opposed to data sent by the
                 host adapter.