drm/msm/mdp5: Add hardware cursor support

This patch implements the hardware accelarated cursor
support for MDP5 platforms.

Signed-off-by: Beeresh Gopal <gbeeresh@codeaurora.org>
Signed-off-by: Wentao Xu <wentaox@codeaurora.org>
Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>