drm/amd/display: Get OTG info if OTG master enabled

Signed-off-by: Logatharshan Thothiralingam <logatharshan.thothiralingam@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>