drm/amd/display: Update OTG instance in the commit stream

drm/amd/display: Update OTG instance in the commit stream

OTG instance is not updated in dc_commit_state_no_check for newly
committed streams because mode_change is not set. Notice that OTG update
is part of the software state, and after hardware programming, it must
be updated; for this reason, this commit updates the OTG offset right
after hardware programming.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Co-developed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>