We might be leaving the GPU Frequency (and thus vnn) high during the suspend.
Force gt to move to lowest freq while suspending.

v2: Fixed typo in commit message (Deepak)

v3: Force gt to lowest freq in suspend_gt_powersave (Daniel)

v4: Add GPU min freq set _after_ we've cancelled the rps works (Daniel)
Signed-off-by: NDeepak S <deepak.s@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>