msm: mdss: fix rotator hang for xrgb formats
msm: mdss: fix rotator hang for xrgb formats

XRGB formats require constant alpha to be setup when writing back to
memory.

Change-Id: Ie819b88578a85923d1cde7efe54ca0819c59a611
Signed-off-by: Adrian Salido-Moreno <f4561ccbe90a02dadc9d168b29bfea0c1b57222c@codeaurora.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas