drm/amd/display: add rc_params_override option in dc_dsc_config

[why]
Current RC params are based on VESA recommended configurations.
Some DSC sink may prefer non standard rc params values due to
hardware limitations. To support those DSC sink we will allow DM to
optionally pass rc_params_ovrd in dc_dsc_config so DC will override
the default VESA recommended configurations.

Reviewed-by: Martin Leung <Martin.Leung@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>