msm: mdss: add rotator writeback ubwc support

The writeback block in the rotator supports ubwc output.
This change enables the client to specify ubwc input and
output format.

Change-Id: Ic9aee90b0edd2128383ecb03cdf7882cd8c8e3e1
Signed-off-by: Xiaoming Zhou <zhoux@codeaurora.org>
Signed-off-by: Terence Hampson <thampson@codeaurora.org>