drm/i915/dp: Add support of BT.2020 Colorimetry to DP MSA

When BT.2020 Colorimetry output is used for DP, we should program BT.2020
Colorimetry to MSA and VSC SDP. In order to handle colorspace of
drm_connector_state, it moves a calling of intel_ddi_set_pipe_settings()
function into intel_ddi_pre_enable_dp(). And it also rename
intel_ddi_set_pipe_settings() to intel_ddi_set_dp_msa().

As per DP 1.4a spec section 2.2.4 [MSA Data Transport]
The MSA data that the DP Source device transports for reproducing the main
video stream. Attribute data is sent once per frame during the main video
stream’s vertical blanking period.

In order to distinguish needed colorimetry for VSC SDP, it adds
intel_dp_needs_vsc_sdp function.
If the output colorspace requires vsc sdp or output format is YCbCr 4:2:0,
it uses MSA with VSC SDP.

As per DP 1.4a spec section 2.2.4.3 [MSA Field for Indication of
Color Encoding Format and Content Color Gamut] while sending
BT.2020 Colorimetry signals we should program MSA MISC1 fields which
indicate VSC SDP for the Pixel Encoding/Colorimetry Format.

v2: Remove useless parentheses
v3: Addressed review comments from Ville
    - In order to checking output format and output colorspace on
      intel_dp_needs_vsc_sdp(), it passes entire intel_crtc_state struct
      value.
    - Remove a pointless variable.
v9: Addressed review comments from Ville
    - Remove a duplicated output color space from intel_crtc_state.
    - In order to handle colorspace of drm_connector_state, it moves a
      calling of intel_ddi_set_pipe_settings() function into
      intel_ddi_pre_enable_dp().

Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190919195311.13972-3-gwan-gyeong.mun@intel.com
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>