cpufreq: Add interface for gov change

* Interface can be used by drivers to change gov.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: limiter: Add controls for per cpu governor

* Requires hooks in CPUFREQ driver.
* Works without limiter enabled.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>