exynos/mfc: add sysmmu power on/off calls

exynos/mfc: add sysmmu power on/off calls

This patch calls the sysmmu driver helper functions for resuming
and suspending its two sysmmus during mfc power on/off. This is required
for the sysmmus to resume/suspend along with the parent mfc device.

BUG=chrome-os-partner:11793
TEST=MFC/GSC/Sysmmu get suspended after probe and resume upon
video playback. Tested on Daisy.

Change-Id: I3faacf3dfc397c72402e9c981ff314007c94887d
Signed-off-by: Prathyush K <prathyush.k@samsung.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/29165
Tested-by: Prathyush Kalashwaram <prathyush@chromium.org>
Reviewed-by: Olof Johansson <olofj@chromium.org>
Commit-Ready: Olof Johansson <olofj@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/42960
Commit-Queue: John Sheu <sheu@chromium.org>
Reviewed-by: John Sheu <sheu@chromium.org>
Tested-by: John Sheu <sheu@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/44767