PM / devfreq: remove compiler error when a governor is module

With the intruction of patch, eff607fdb1f787da1fedf46ab6e64adc2afd1c5a,
it became possible to include a governor as a module.
Thus the #ifdef statement for a governor should become #if IS_ENABLED.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
1 file changed