Set Witherspoon hwmon target mode

Set the target mode for the MAX31785 fan controller
device to be RPM mode so phosphor-hwmon doesn't also
create an interface for PWM control.

Resolves openbmc/openbmc#2940

Tested: Used this config file with the corresponding
        phosphor-hwmon changes and ensured the correct
        interface was created.

Change-Id: I6a1361e0264dde252b838c6428fae8b921e0d381
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
1 file changed