Documentation: devicetree: add max6621 device

Add device record for Maxim MAX6621 temperature sensor device.
Signed-off-by: NVadim Pasternak <vadimp@mellanox.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Documentation/devicetree/bindings/trivial-devices.txt

@@ -71,6 +71,7 @@ isil,isl29028		Intersil ISL29028 Ambient Light and Proximity Sensor
 isil,isl29030		Intersil ISL29030 Ambient Light and Proximity Sensor
 maxim,ds1050		5 Bit Programmable, Pulse-Width Modulator
 maxim,max1237		Low-Power, 4-/12-Channel, 2-Wire Serial, 12-Bit ADCs
+maxim,max6621		PECI-to-I2C translator for PECI-to-SMBus/I2C protocol conversion
 maxim,max6625		9-Bit/12-Bit Temperature Sensors with I²C-Compatible Serial Interface
 mc,rv3029c2		Real Time Clock Module with I2C-Bus
 mcube,mc3230		mCube 3-axis 8-bit digital accelerometer