drm/msm/sde: add danger/safe/QoS support for source pipe

QoS control enables source pipe to map request priority based on
source pipe file level using lookup table.  Danger/safe control
enables source pipe to provide additional signal based on
buffer fill information for fabric prioritization over other
bus clients.

Change-Id: I95f1da4f5f79eded62c7b39aba23a7ce8363987f
Signed-off-by: Alan Kwong <akwong@codeaurora.org>