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/msm_fb.c
msm_fb: display: add pipe commit ioctl

currently, pan display serves as pipe commit. However it
may spend long time pending on cosole_lock() which cause
flickering on HDMI. Add pipe commit ioctl to allow commit
from overlay in addition to pan_display.

CRs-fixed: 391564
Change-Id: I163b5d96f727b70b4d5693e9a414b59339818998
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
(cherry picked from commit a77eca6cee55531e81e21d83b474563f9c143e77)

Signed-off-by: Dhivya Subramanian <dthiru@codeaurora.org>