drm/i915: Honor i915_min_freq post resume

drm/i915: Honor i915_min_freq post resume

The i915_min_freq setting was not getting honored on the resume path.
Fixed it.

BUG=chrome-os-partner:16439
TEST="cat /sys/kernel/debug/dri/0/i915_min_freq" and remember the value
returned. Do a suspend/resume cycle. cat the i915_min_freq file again,
it must return the same value as read earlier.

Original-Change-Id: Ie3cc8e8794a59c154b511e24e468daef94a44765
Signed-off-by: Sameer Nanda <snanda@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/41461
(cherry picked from commit b57da6083079196f955b8217517afd0e1e4a0e21)

Change-Id: I608349c9f7983c24bafa0f9883384cd7c6545f83
Reviewed-on: https://gerrit.chromium.org/gerrit/41572
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Commit-Queue: Sameer Nanda <snanda@chromium.org>
Tested-by: Sameer Nanda <snanda@chromium.org>