This fixes corrupted display output in HDMI deep color
10/12 bpc mode at least as observed on AMD Mullins, DCE-8.3.

It will hopefully also provide fixes for other DCE's up to
DCE-11, assuming those will need similar fixes, but i could
not test that for HDMI due to lack of suitable hw, so viewer
discretion is advised.

dce110_stream_encoder_hdmi_set_stream_attribute() is used for
HDMI setup on all DCE's and is missing color_depth assignment.

dce110_program_pix_clk() is used for pixel clock setup on HDMI
for DCE 6-11, and is missing color_depth assignment.

Additionally some of the underlying Atombios specific encoder
and pixelclock setup functions are missing code which is in
the classic amdgpu kms modesetting path and the in the radeon
kms driver for DCE6/DCE8.

encoder_control_digx_v3() - Was missing setup code wrt. amdgpu
and radeon kms classic drivers. Added here, but untested due to
lack of suitable test hw.

encoder_control_digx_v4() - Added missing setup code.
Successfully tested on AMD mullins / DCE-8.3 with HDMI deep color
output at 10 bpc and 12 bpc.

Note that encoder_control_digx_v5() has proper setup code in place
and is used, e.g., by DCE-11.2, but this code wasn't used for deep
color setup due to the missing cntl.color_depth setup in the calling
function for HDMI.

set_pixel_clock_v5() - Missing setup code wrt. classic amdgpu/radeon
kms. Added here, but untested due to lack of hw.

set_pixel_clock_v6() - Missing setup code added. Successfully tested
on AMD mullins DCE-8.3. This fixes corrupted display output at HDMI
deep color output with 10 bpc or 12 bpc.

Fixes: 4562236b ("drm/amd/dc: Add dc display driver (v2)")
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>