cpufreq: interface for setting governor for a cpu

This implementation sets governor for a cpu using existing
cpufreq interfaces.

bug 871958

Change-Id: Ic4e7e2a2b0babaf1829b559b5db211666d449b86
Signed-off-by: Puneet Saxena <puneets@nvidia.com>
Reviewed-on: http://git-master/r/97939
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>

Rebase-Id: Rb3099a95700c83e412808b91da1c076f0873722c
Signed-off-by: Jake Weinstein <xboxlover360@gmail.com>

Conflicts:
	include/linux/cpufreq.h

Signed-off-by: Jake Weinstein <xboxlover360@gmail.com>