drm/amdgpu: use memcpy_toio for VCE firmware upload

Try to be clean here, even when it's a noop on x86.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c
index 05865ce..da52af2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vce.c
@@ -282,8 +282,8 @@
 
 	hdr = (const struct common_firmware_header *)adev->vce.fw->data;
 	offset = le32_to_cpu(hdr->ucode_array_offset_bytes);
-	memcpy(cpu_addr, (adev->vce.fw->data) + offset,
-		(adev->vce.fw->size) - offset);
+	memcpy_toio(cpu_addr, adev->vce.fw->data + offset,
+		    adev->vce.fw->size - offset);
 
 	amdgpu_bo_kunmap(adev->vce.vcpu_bo);