msm: kgsl: drm: Increased max sub-buffers allowed to 3
msm: kgsl: drm: Increased max sub-buffers allowed to 3

To permit triple buffering, number of allowed sub-buffers
was increased to 3 from 2.

Change-Id: I0d70df7b1ecad438280c9560d9b70354f3681d8f
Signed-off-by: Michael Street <861f853c8963703e45a164732e73a703905211c5@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