It adds routines that write DP VSC SDP and DP HDR Metadata Infoframe SDP.
In order to pack DP VSC SDP, it adds intel_dp_vsc_sdp_pack() function.
It follows DP 1.4a spec. [Table 2-116: VSC SDP Header Bytes] and
[Table 2-117: VSC SDP Payload for DB16 through DB18]

In order to pack DP HDR Metadata Infoframe SDP, it adds
intel_dp_hdr_metadata_infoframe_sdp_pack() function.
And it follows DP 1.4a spec.
([Table 2-125: INFOFRAME SDP v1.2 Header Bytes] and
[Table 2-126: INFOFRAME SDP v1.2 Payload Data Bytes - DB0 through DB31])
and CTA-861-G spec. [Table-42 Dynamic Range and Mastering InfoFrame].

A mechanism and a naming rule of intel_dp_set_infoframes() function
references intel_encoder->set_infoframes() of intel_hdmi.c .
VSC SDP is used for PSR and Pixel Encoding and Colorimetry Formats cases.
Because PSR routine has its own routine of writing a VSC SDP, when the PSR
is enabled, intel_dp_set_infoframes() does not write a VSC SDP.

v3:
  - Explicitly disable unused DIPs (AVI, GCP, VS, SPD, DRM. They will be
    used for HDMI), when intel_dp_set_infoframes() function will be called.
  - Replace a structure name to drm_dp_vsc_sdp from intel_dp_vsc_sdp.
v4: Use struct drm_device logging macros
v5:
  - use intel_de_*() functions for register access
  - Addressed review comments from Uma
    Polish commit message and comments
    Add 6bpc to packing of VSC SDP
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/20200211074657.231405-5-gwan-gyeong.mun@intel.com