msm: mdss: Wait for vsync before iommu attach during cont splash

During first borderfill commit in splash cleanup, wait for vsync
before iommu attach to prevent IOMMU page faults during bootup.

Change-Id: I68b7162d090513b082cbd4c0013731cedc0ebdbe
Signed-off-by: Jayant Shekhar <jshekhar@codeaurora.org>
Signed-off-by: Vineet Bajaj <vbajaj@codeaurora.org>
msm: mdss: Check null-pointer dereferencing and buffer overflows

Add checks before possible null-pointer dereferencing. Add checks to
prevent buffer out-of-bounds access.

Change-Id: I17419c82654c4ad2d18c7f88e34447cf333450bb
Signed-off-by: Mathew Karimpanal <kjmathew@codeaurora.org>
Signed-off-by: Beeresh Gopal <gbeeresh@codeaurora.org>