hwmon: (pmbus) Add support for additional Flex BMR converters to pmbus

Add support for Flex BMR310, BMR456, BMR457, BMR458, BMR480, BMR490,
BMR491 and BMR492 to the pmbus driver

Signed-off-by: Erik Rosen <erik.rosen@metormote.com>
Link: https://lore.kernel.org/r/20210507194023.61138-4-erik.rosen@metormote.com


[groeck: Fixed minor whitespace error]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>