PM / devfreq: Allow the governors to set the target flag

The devfreq framework calls a frequency targeting function with
a flag parameter.  Allow the governors to influence that parameter.

Change-Id: I4058bd9dcd027dd246ccdb90d25c68f1dc055901
Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>

idea is taken here - https://github.com/faux123/moto_g/commit/3b6ee299e1b5b456d5b01c56f4a73ff8dc100c22