CHROMIUM: fix 800x600 resolution for exynos5 hdmi

CHROMIUM: fix 800x600 resolution for exynos5 hdmi

800x600 resolution is not cleanly supported by the exynos5 mixer block.
Hw team suggested following workaround to enable the above resolution.

1) In MIXER_CFG register, set HD_SD and HD_MODE bits to 1.
2) In MIXER0_GRAPHIC0_DXY, set MIXER0_GRP0_DX to 32.
3) In MIXER_TVOUT_CFG, Change 3D one path mode to 3D two path AFTER 1 FRAME.

BUG=chrome-os-partner:12643 & chromium:225983
TEST:
1) Booted with HDMI Connectd to Sink that supports only 800x600
2) HDMI Unplug-plug scenarios
3) S2R by running powerd_dbus_suspend

Change-Id: Ic5952ff3982c4923eabb69febeabfeb445e7a79c
Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
Signed-off-by: Shirish S <s.shirish@samsung.com>
Signed-off-by: Akshay Saraswat <Akshay.s@samsung.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/47650
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Tested-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Shirish S <shirish@chromium.org>