msm: rotator: Add BGRX_8888 format support

Rotator hardware supports BGRX_8888 format.
Add software support for this format in driver.

Change-Id: Ib9802344f5acfb25d2b18645610e37a640e2f9d5
Signed-off-by: Pawan Kumar <pavaku@codeaurora.org>