drm/amdgpu: add missing radeon secondary PCI ID

0x5b70 is a missing RV370 secondary id.  Add it so
we don't try and probe it with amdgpu.

Cc: michel@daenzer.net
Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>
Tested-by: Michel Dänzer <mdaenzer@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c

@@ -1615,6 +1615,7 @@ static const u16 amdgpu_unsupported_pciidlist[] = {
 	0x5874,
 	0x5940,
 	0x5941,
+	0x5b70,
 	0x5b72,
 	0x5b73,
 	0x5b74,