ARM: exynos: Change snow LCD timings to get 60Hz

ARM: exynos: Change snow LCD timings to get 60Hz

Tweak the LCD timings on snow to get a 60Hz refresh rate. We were
previously running at 52Hz because the timings weren't correct.
We have to use out-of-spec horizontal margins (0 instead of 30) to
get up to 60Hz. The panel seems to work well with these values.

BUG=None
TEST=Tested on snow

Change-Id: If92f7a8bdacb811cbbe948393caa1b4ab248ba2f
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/27681
Reviewed-by: Anush Elangovan <anush@google.com>
Tested-by: Anush Elangovan <anush@google.com>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>