drm/msm/dp: fix HDR programming

Add extension SDP programming. Generate parity byte for a
corresponding header byte and program the hardware accordingly
to fix the HDR related issues.

Change-Id: Ifad8cfb8abee9fe498d57aca918d39055d2b27fb
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>