hwmon: (pmbus) Add IC_DEVICE_ID and IC_DEVICE_REV command definitions

Recent PMBus versions added IC_DEVICE_ID and IC_DEVICE_REV commands as
additional means to identify the chip. Add command definitions to
pmbus.h include file.

Cc: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/pmbus/pmbus.h

@@ -119,6 +119,9 @@ enum pmbus_regs {
 	PMBUS_MFR_DATE			= 0x9D,
 	PMBUS_MFR_SERIAL		= 0x9E,
 
+	PMBUS_IC_DEVICE_ID		= 0xAD,
+	PMBUS_IC_DEVICE_REV		= 0xAE,
+
 /*
  * Virtual registers.
  * Useful to support attributes which are not supported by standard PMBus