drm/i915/dp: Add compute routine for DP PSR VSC SDP

In order to use a common VSC SDP Colorimetry calculating code on PSR,
it adds a compute routine for PSR VSC SDP.
As PSR routine can not use infoframes.vsc of crtc state, it also adds new
writing of DP SDPs (Secondary Data Packet) for PSR.
PSR routine has its own scenario and timings of writing a VSC SDP.

v3: Replace a structure name to drm_dp_vsc_sdp from intel_dp_vsc_sdp
v4: Use struct drm_device logging macros
v10: 1) Fix packing of VSC SDP where Pixel Encoding/Colorimetry Format is
        not supported.
     2) Change a checking of PSR state.

Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200514060732.3378396-14-gwan-gyeong.mun@intel.com