drm/amd/display: Add missing dcn35 RCO registers

[Why]
Some registers needed for root clock gating in dcn35 are not defined in
the dccg header.

[How]
Add the needed registers and temporarily disable some register writes
that are now taking place successfully until the registers can be
properly enabled.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Charlene Liu <charlene.liu@amd.com>
Acked-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Daniel Miess <daniel.miess@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Enable DCN clock gating for DCN35

[WHY & HOW]
Enable DCN clock gating for DCN35.
Disable DTBCLK gate before link training
and re-enable afterwards

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Daniel Miess <daniel.miess@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Enable physymclk RCO

[Why]
Enable the last of the RCO options for dcn35

[How]
Breakout RCO from dccg35_set_physymclk so that
physymclk RCO can be set in dccg_init without
disabling physymclk

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Jun Lei <jun.lei@amd.com>
Acked-by: Hersen Wu <hersenxs.wu@amd.com>
Signed-off-by: Daniel Miess <daniel.miess@amd.com>
Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Enable RCO options for dcn35

[Why & How]
Enable root clock optimization options for dcn35
for power savings

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Hersen Wu <hersenxs.wu@amd.com>
Signed-off-by: Daniel Miess <daniel.miess@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Fix DP2.0 timing sync

[Why]
Triggering OTG sync before all OTG/HPO clock programming is complete
causes timing sync to fail and a subsequent P-state hang.

[How]
Move DTB clock programming earlier in the sequence to
enable_stream_timing.

Reviewed-by: Ariel Bernstein <eric.bernstein@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Ilya Bakoulin <ilya.bakoulin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Fix MST recognizes connected displays as one

MST now recognizes both connected displays

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Charlene Liu <charlene.liu@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Muhammad Ahmed <ahmed.ahmed@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Add reset for SYMCLKC_FE_SRC_SEL

To prevent confusion after symclk has already been disabled.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Taimur Hassan <syed.hassan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Add DCN35 DCCG

[Why & How]
Add DCCG handling for DCN35.

Signed-off-by: Qingqing Zhuo <Qingqing.Zhuo@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>