cpufreq: Make get governor interface always return good value

* In rare scenario, we may not able to lock policy
  and in such case, get governor interface returns
  "invalid" governor.
* This patch ensures we never get "invalid" governor.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: limiter: Do not store governor locally

* @RenderBroken reported that local variables do
  not reflect actual value on boot.
* This happens because ramdisk or userspace apps
  change scaling_governor by using following path
  /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
* When above path is updated with new governor, local
  variables in limiter driver are not.
* Drop local variables and reflect actual governor per
  core always.

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