cpufreq: Preserve sysfs min/max request

Store the value received via sysfs as the user_policy
min/max value instead of the currently enforced min/max.
This allows restoring the user min/max values when
constraints on enforced min/max change.

Bug 888312

Change-Id: I8a5adf022585e5bd91fa3b1d8d448065efa6827a
Reviewed-on: http://git-master/r/73982
Signed-off-by: Antti P Miettinen <amiettinen@nvidia.com>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Reviewed-on: http://git-master/r/75886
Reviewed-by: Automatic_Commit_Validation_User

Rebase-Id: Ra33b58958c1251c5931e84c2a81726fe9b5b1e92

Conflicts:
	drivers/cpufreq/cpufreq.c