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: On boot disable domain22 force power on

[Why]
HDCP2 enablement fails when domain22 is set to force
power on

[How]
Disable force power on for domain22 on startup

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 copyright notice in DC code

[Why & How]
Fix incomplete copyright notice in DC code.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Add DCN35 PG_CNTL

[Why & How]
Add PG_CNTL 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>