msm: mdss: Add scalar data structure to enable scalar programming

mdp_scale_data is a data structure added to mdp_overlay structure
to receive scalar factors for the QSEED filter such as
initial phase, phase step and pixel extension from the userland.
This data is need to achieve image clarity when using the scalar.

Signed-off-by: Sree Sesha Aravind Vadrevu <svadrevu@codeaurora.org>
Change-Id: I88e5e0cc9f4e604f38fa7c35a6a93378d3b55050