drm/amd/powerplay: add BACO platformCaps for VEGA20

BACO reset is needed for RAS recovery.

Signed-off-by: Le Ma <le.ma@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>