drm/amd/pm: add mode1 support for beige_goby

Add mode1 reset as the default reset method for beige_goby

Signed-off-by: Chengming Gui <Jack.Gui@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>