msm: mdss: smooth splash hand-off LK to kernel

This change enables the smooth splash image hand-off
from LK to kernel.

To display the splash image same memory is reserved
for both DSI0 and DSI1, so during the handoff when this
memory was freed for DSI0. A glitch was observed on DSI1,
because DSI1 was still using the splash mem.
As the DSI-1 clean up happens at the last, hence delaying the
cleanup till last DSI interface.

Change-Id: I47aaa54c7c6d5dd3e8e984ad06a3c19925f871f9
Signed-off-by: Rahul Sharma <sharah@codeaurora.org>