Driver uses only VSYNC interrupts, so we need to cache VSYNC bit state only.
Signed-off-by: NAndrzej Hajda <a.hajda@samsung.com>
Reviewed-by: NJoonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: NInki Dae <inki.dae@samsung.com>