drm/amdgpu: rename rlc autoload to backdoor autoload

This is to differentiate rlc backdoor autoload from rlc
frontdoor autoload
Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Le Ma <Le.Ma@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -247,7 +247,7 @@ enum amdgpu_firmware_load_type {
 	AMDGPU_FW_LOAD_DIRECT = 0,
 	AMDGPU_FW_LOAD_SMU,
 	AMDGPU_FW_LOAD_PSP,
-	AMDGPU_FW_LOAD_RLC_AUTO,
+	AMDGPU_FW_LOAD_RLC_BACKDOOR_AUTO,
 };
 
 /* conform to smu_ucode_xfer_cz.h */