hwmon: (max6639) : Add additional hwmon attributes for fan and pwm

Add additional attributes for fan & pwm i.e.,
fanY_pulses
pwmY_freq

Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
Link: https://lore.kernel.org/r/20240614055533.2735210-2-naresh.solanki@9elements.com


[groeck: Fix value range for fanX_pulses]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>