hwmon: (emc2305) Add support for PWM frequency, polarity and output

Add three new attributes to the driver data structures to support
configuration of PWM frequency, PWM polarity and PWM output config.

Signed-off-by: Florin Leotescu <florin.leotescu@nxp.com>
Link: https://lore.kernel.org/r/20250603113125.3175103-2-florin.leotescu@oss.nxp.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>