drm/amd/display: Various DML2 fixes for FAMS2

The disable fams2 operation was reworked, but some of the old code
remained. This commit removes the disable_fams2_drr from the
dml2_stream_parameters.

Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Dillon Varone <dillon.varone@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>