MIPS: ath25: add common parts

Add common code for Atheros AR5312 and Atheros AR2315 SoCs families.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Linux MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/8237
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/ath25/prom.c b/arch/mips/ath25/prom.c
new file mode 100644
index 0000000..edf82be
--- /dev/null
+++ b/arch/mips/ath25/prom.c
@@ -0,0 +1,26 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright MontaVista Software Inc
+ * Copyright (C) 2003 Atheros Communications, Inc.,  All Rights Reserved.
+ * Copyright (C) 2006 FON Technology, SL.
+ * Copyright (C) 2006 Imre Kaloz <kaloz@openwrt.org>
+ * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
+ */
+
+/*
+ * Prom setup file for AR5312/AR231x SoCs
+ */
+
+#include <linux/init.h>
+#include <asm/bootinfo.h>
+
+void __init prom_init(void)
+{
+}
+
+void __init prom_free_prom_memory(void)
+{
+}