This adds colorspace information to HDMI AVI infoframe.
A helper function is added to program the same.

v2: Moved this to drm core instead of i915 driver.

v3: Exported the helper function.

v4: Added separate HDMI specific macro as per CTA spec.
This is separate from user exposed enum values. This is
as per Ville's suggestion.

v5: Appended BT709 and SMPTE 170M with YCC information as per Ville's
review comment to be clear and not to be confused with RGB.

v6: Added bit wise macro for various fields of colorimetry for easier
understanding and review as per Ville's comments. Moved the same out of
header file to avoid any namespace issues.

v7: Undef some macros to avoid any namespace collision as suggested by
Ville. Added Ville's RB.
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1550596381-993-3-git-send-email-uma.shankar@intel.com