drm/amdgpu: Initialize dce_virtual_ip_funcs

For virtual display feature, first need to initialize dce_virtual_ip_funcs,
which will be used when set ip blocks.

Signed-off-by: Emily Deng <Emily.Deng@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/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
index c7fcdce..21dd7c0 100644
--- a/drivers/gpu/drm/amd/amdgpu/Makefile
+++ b/drivers/gpu/drm/amd/amdgpu/Makefile
@@ -58,7 +58,8 @@
 # add DCE block
 amdgpu-y += \
 	dce_v10_0.o \
-	dce_v11_0.o
+	dce_v11_0.o \
+	dce_virtual.o
 
 # add GFX block
 amdgpu-y += \