Add sepolicy for gpu_device

 * Not needed on QCOMs, but RK needs this.

Change-Id: Ieb8f17dfd966db3a694120cdade9e2913b3ca0a5

sepolicy/vncflinger.te

@@ -18,3 +18,6 @@ binder_call(surfaceflinger, vncflinger);
 
 # socket
 allow vncflinger rootfs:lnk_file getattr;
+
+# gpu access (needed on rk)
+allow vncflinger gpu_device:chr_file { ioctl open read write };