drm/meson: fix colour distortion from HDR set during vendor u-boot

drm/meson: fix colour distortion from HDR set during vendor u-boot

Add support for the OSD1 HDR registers so meson DRM can handle the HDR
properties set by Amlogic u-boot on G12A and newer devices which result
in blue/green/pink colour distortion to display output.

This takes the original patch submissions from Mathias [0] and [1] with
corrections for formatting and the missing description and attribution
needed for merge.

[0] https://lore.kernel.org/linux-amlogic/59dfd7e6-fc91-3d61-04c4-94e078a3188c@baylibre.com/T/
[1] https://lore.kernel.org/linux-amlogic/CAOKfEHBx_fboUqkENEMd-OC-NSrf46nto+vDLgvgttzPe99kXg@mail.gmail.com/T/#u

Fixes: 728883948b0d ("drm/meson: Add G12A Support for VIU setup")
Suggested-by: Mathias Steiger <mathias.steiger@googlemail.com>
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Philip Milev <milev.philip@gmail.com>
[narmsrong: adding missing space on second tested-by tag]
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210806094005.7136-1-christianshewitt@gmail.com