drm/amdgpu/display: fix dependencies for DRM_AMD_DC_SI

Depends on DRM_AMDGPU_SI and DRM_AMD_DC
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/Kconfig

@@ -25,6 +25,8 @@ config DRM_AMD_DC_HDCP
 
 config DRM_AMD_DC_SI
 	bool "AMD DC support for Southern Islands ASICs"
+	depends on DRM_AMDGPU_SI
+	depends on DRM_AMD_DC
 	default n
 	help
 	  Choose this option to enable new AMD DC support for SI asics