msm: mdss: Make vsync wait non-interruptible in video_wait4comp

Currently in MDSS driver, vsync wait is getting interrupted due
to which input buffer to RGB pipe is getting unmapped/freed even
when the pipe is still connected to LM0 resulting in IOMMU fault.
So, making the vsync wait non-interruptible fixes the issue.

CRs-Fixed: 510352
Change-Id: I16d157079cc943ddfddc27a5317fc26c4fee1f0b
Signed-off-by: Jayant Shekhar <jshekhar@codeaurora.org>