disp: msm: sde: update cwb checks for destination scaler

Current validation checks for cwb are not complete for
destination scaler concurrency. This change fixes cwb
checks to handle wb roi and frame buffer bounds checks
based on tap point and the destination scaler use.

Change-Id: I4a0277fea262621e73459243f60d3018bc475a67
Signed-off-by: Prabhanjan Kandula <pkandula@codeaurora.org>