msm: mdss: Add support for VBIF QoS remapper

Each MDP source pipe can generate 4 levels of priority
and those priorities are remapped before reaching the
AXI bus. These re-mapper settings depends on the chip-set
and the nature of the control path source pipe is used
in. Ex. re-mapper value for DMA pipe used in DSI,
real-time control path, will be different than DMA pipe
used in rotator, non-real-time control path. Provide
support to implement this configuration.

Change-Id: I254f76dd47e3c41adde9894a23232e2f83e6b79c
Signed-off-by: Jayant Shekhar <jshekhar@codeaurora.org>