drm: dp: add support to validate the modes reported by the sink

The Display Port driver might not support all the modes returned by
the sink upon reading its EDID. This can be due to a combination of
restrictions related to link rate/number of lanes/bpp/maximum pixel
clock supported by the SDM hardware. Add support to validate these
modes before passing them to display userspace system.

Change-Id: Ia1cfb8dcd293b89405718dd68fb53e6d3b000ad5
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>