intel: rename ptr_opaque to ptr

It is void * and is opqaue already.
diff --git a/icd/intel/cmd.h b/icd/intel/cmd.h
index 698f1b8..4d9daf7 100644
--- a/icd/intel/cmd.h
+++ b/icd/intel/cmd.h
@@ -200,7 +200,7 @@
 
 struct intel_cmd_writer {
     struct intel_bo *bo;
-    void *ptr_opaque;
+    void *ptr;
 
     /* in DWords */
     XGL_UINT size;