msm_fb: display: Add pseudo-planar 422 H1V2 support in the MDP4

Rotator outputs pseudo-planar 422 H1V2 for interleaved inputs
on 90 degree rotation. Add changes to support MDP_Y_CRCB_H1V2
in MDP4.

CRs-Fixed: 371303
Change-Id: I8083bf44f9e2addf9e8732268147c1c3f6c0e2af
Signed-off-by: Mayank Chopra <makchopra@codeaurora.org>
Revert "msm_fb: display: remove background invert alpha option for alpha drop pipe"

This reverts commit 651b4d257ce12f26827ef995a90767d3454228a6.
Revert "msm_fb: display: add per stage alpha drop detection"

This reverts commit fec3b0205540a2f836655e1aac74d6b206ec2709.
Fix a mistake made while reverting a commit
msm_fb: Use background alpha for all destination alpha enable cases

Use background alpha for modulation in all the cases where source alpha
is not available.

CRs-fixed: 366834
Change-Id: I300c04181ee3fa4f305a26a3e17e7eac2572564c
Signed-off-by: Kalyan Thota <kalyant@codeaurora.org>

Conflicts:

	drivers/video/msm/mdp4_overlay.c
msm: display: plane alpha support

Clean up the blending rule to follow blend_op set from hwc.
Use modulate alpha for plane alpha when it is not 0xff.
Keep backward compatibility if blend_op is not set.

Change-Id: I02fd3c3c7b5ace2e6eec22b2db0284161404a0fc
Signed-off-by: Ken Zhang <kenz@codeaurora.org>
Signed-off-by: Naseer Ahmed <naseer@codeaurora.org>

Conflicts:

	drivers/video/msm/mdp4_overlay.c