drm/exynos/mixer: fix synchronization check in interlaced mode

drm/exynos/mixer: fix synchronization check in interlaced mode

BugLink: http://bugs.launchpad.net/bugs/1794889
[ Upstream commit 2eced8e917b060587fc8ed46df41c364957a5050 ]

In case of interlace mode video processor registers and mixer config
register must be check to ensure internal state is in sync with shadow
registers.
This patch fixes page-faults in interlaced mode.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>