msm_fb: Add "Continuous Splash Screen" support for LCDC panel

Add changes to support continuous splash screen on 8x25 SKU7
for LCDC panel. Delay the MDP hardware initialisation,
keep LCDC timing generator enable during boot up, do not
disturb the GPIO/regulator configurations and skip the
panel initialization sequence during boot up.

Change-Id: Ied091b01ad2f26acdff73e3ffe158d844198923c
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>