drm/msm/mdp5: Add more stuff to CRTC state

Things like vblank/err irq masks, mode of operation (command mode or not)
are derivative of the interface and mixer state. Therefore, they need to
be a part of the CRTC state too.

Add them to mdp5_crtc_state, and assign them in the CRTC's atomic_check()
func, so that it can be rolled back to a clean state.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>