drm/amd/display: Add support for manual DMUB FAMS trigger

- Add is_drr parameter to indicate DRR is enabled on
the panel to determine whether SubVP MCLK switch
logic should be enabled

- Add DRR manual trigger in FW (instead of driver)
because manual trigger programming triggers DRR
update pending and can block SubVP MCLK switches
from taking place

Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>