msm: mdss: Add support for different voting on RT/NRT AXI Ports

In 8939, MDSS has two AXI Ports one for real time client and the other
for non-real time clients. Bandwidth required on each of the port changes
according to the use case which necessitates the voting to separate on two
different ports. Separate vote is calculated for RT clients and NRT clients
which will be voted on respective ports.

Change-Id: If3d3d670c19a03d5d9659db6e3630a2958744f07
Signed-off-by: Vishnuvardhan Prodduturi <vproddut@codeaurora.org>