drivers: cpufreq: Upstream optimizations

* Clean up and optimize cpufreq driver.
* This is needed for good multi cpu
  policy control via msm limiter.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: limiter: Introduce initial multi cpu control

* This extends current functionality of the driver
  to save min/max freq for each core.
* Disabled by default.
* CPU0 is master boot core for 3.4 kernel and user
  should not reduce max freq of this core more than
  half of range.

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