disp: uapi: drm: Add new blend type for CAC

Change adds new blend type for CAC to perform
blending operation on layer color components.

Change-Id: I194e1a7953dd5828fc9ae374aa6b6f7f1bf0eb37
Signed-off-by: Govinda Rao K S <quic_gkarikur@quicinc.com>
Signed-off-by: Prashant Beniwal <quic_pbeniw@quicinc.com>