drm/amdgpu: support rlc auotload type set

Support to set fw_load_type=3 to use backdoor
rlc autoload.

Signed-off-by: Likun Gao <[e-mail]>
Reviewed-by: Hawking Zhang <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

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

···
 	default:
 		if (!load_type)
 			return AMDGPU_FW_LOAD_DIRECT;
+		else if (load_type == 3)
+			return AMDGPU_FW_LOAD_RLC_BACKDOOR_AUTO;
 		else
 			return AMDGPU_FW_LOAD_PSP;
 	}