drm:msm:sde allow qsync support along with VRR

Allow Qsync and VRR features to be supported independently
by display driver. Restrict the feature availability in
the same composition cycle.

Change-Id: I696eb72a2b4f9451e142ffdc5acccc8987c36b6d
Signed-off-by: Kalyan Thota <kalyant@codeaurora.org>