Fix FF-A spec reference in comment.

The chapters were renumbered since this comment was written.

Change-Id: Ie57b057a3539aabcbe6135e0361cc26779896777
diff --git a/src/ffa_memory.c b/src/ffa_memory.c
index 499f6c0..aeea137 100644
--- a/src/ffa_memory.c
+++ b/src/ffa_memory.c
@@ -1416,9 +1416,9 @@
 			return ffa_error(FFA_INVALID_PARAMETERS);
 		}
 		/*
-		 * According to section 6.11.3 of the FF-A spec NX is required
-		 * for share operations (but must not be specified by the
-		 * sender) so set it in the copy that we store, ready to be
+		 * According to section 5.11.3 of the FF-A 1.0 spec NX is
+		 * required for share operations (but must not be specified by
+		 * the sender) so set it in the copy that we store, ready to be
 		 * returned to the retriever.
 		 */
 		ffa_set_instruction_access_attr(permissions,