drm/amd: Avoid BUG() for case of SRIOV missing IP version

No need to crash the kernel.  AMDGPU will now fail to probe.
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -381,7 +381,7 @@ static int psp_init_sriov_microcode(struct psp_context *psp)
 		adev->virt.autoload_ucode_id = AMDGPU_UCODE_ID_CP_MES1_DATA;
 		break;
 	default:
-		BUG();
+		ret = -EINVAL;
 		break;
 	}
 	return ret;