drm/msm/sde: fix issues with the cdm configuration

This change adds support for configuring the pp block id
which will feed the pixels to cdm block in the current
control path configuration. This change addtionally fixes
cdm programming in the interface configuration implementation.

Change-Id: If5491b1cc806d66ef4601cfda7122a0484d123d6
Signed-off-by: Abhijit Kulkarni <kabhijit@codeaurora.org>