HAOC: Add log message when HAOC is enabled

When HAOC  is enabled via kernel  command line, print an informational message to dmesg.
This helps in verifying the feature status during boot.

Author: ecjtusbs

arch/x86/mm/init_64.c

@@ -1392,8 +1392,10 @@ void __init mem_init(void)
 	 * The upper region becomes the IEE linear mapping area.
 	 * Note that the IEE mapping region is mapped with read-only permissions.
 	 */
-	if (haoc_enabled)
+	if (haoc_enabled) {
+		pr_info("HAOC is enabled by kernel command line.");
 		iee_init();
+	}
 	#endif
 	preallocate_vmalloc_pages();
 }