PM / devfreq: passive: Reduce duplicate code when passive_devfreq case

In order to keep the consistent coding style between passive_devfreq
and passive_cpufreq, use common code for handling required opp property.
Also remove the unneed conditional statement and unify the comment
of both passive_devfreq and passive_cpufreq when getting the target frequency.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
1 file changed