[vdi] Refactor texture/surface reference support.

Change-Id: I8014d82aae7139ef5f95e4b50c4fc6da200dbc9d

samples/2_Cookbook/11_texture_driver/tex2dKernel.cpp

@@ -21,11 +21,7 @@ THE SOFTWARE.
 */
 
 #include "hip/hip_runtime.h"
-#if __HIP__
-__hip_pinned_shadow__
-#else
-extern
-#endif
+
 texture<float, 2, hipReadModeElementType> tex;
 
 extern "C" __global__ void tex2dKernel(float* outputData, int width, int height) {