msm_fb: display: fix division-by-zero bug

Panel v_back_porch could be zero for virtual panels, so the check for
zero is added to fix the bug.

Change-Id: I6a29f3d8d771092bca2374cc9a1c11dd77ad569e
Signed-off-by: Huaibin Yang <huaibiny@codeaurora.org>
msm_fb: display: Add timeout for waiting on update

Content Adaptive BackLight userspace algo waits on UPDATE_NOTIFY to
get the screen updates. When turning off CABL, this blocking ioctl
causes the CABL threads to wait until next screen update, which may
take indefinite time.

Add timeout value to the wait_for_completion call, to make ioctl
call blocking for at most timeout value.

CRs-Fixed: 384026
Change-Id: I6715a36020c24ddd09823bd54d4321900429a6b9
Signed-off-by: Kinjal Bhavsar <kbhavsar@codeaurora.org>

Conflicts:

	drivers/video/msm/msm_fb.c
msm: display: fb blend setting via MSMFB_METADATA_SET ioctl

MSMFB_METADATA_SET ioctl is added for the fb user to pass
in additional infomation rather than using reserved
fields.
User can set pre-multiplied alpha for the frame buffer via this
ioctl, overlay blend setting will take this into account.

Change-Id: Ic2f6236d84691fb03174ec479874c6928489ea30
Signed-off-by: Ken Zhang <kenz@codeaurora.org>

Conflicts:

	drivers/video/msm/mdp4_overlay.c
	drivers/video/msm/mdp4_util.c
	drivers/video/msm/msm_fb.c