intel: include obj.h in mem.h

For intel_base.
diff --git a/icd/intel/mem.h b/icd/intel/mem.h
index 10b5580..d6e9aa3 100644
--- a/icd/intel/mem.h
+++ b/icd/intel/mem.h
@@ -27,6 +27,7 @@
 
 #include "kmd/winsys.h"
 #include "intel.h"
+#include "obj.h"
 
 struct intel_mem {
     struct intel_base base;