drm/amdgpu/vega20: use mode1 reset for RAS and XGMI

If RAS or XGMI are enabled, you have to use mode1 reset rather
than BACO.

Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>