msm: mdss: Check if PP has split mode enabled for PAv2 features

The option for split mode in PP only checks the enable flag of the
feature in order to enable the same in the DSPP opmode. The opmode bits for
PAv2 features need to be disabled if PA bit is disabled.

Change-Id: I72019d0d03703e0698cf8d4ccd8b8f9c17889653
Signed-off-by: Benet Clark <benetc@codeaurora.org>