mips: ath79: Add AR934x support

Add support for the Atheros AR934x WiSoCs. This patchs adds complete
system init, including PLL and DRAM init, both of which happen from
full C environment, since the AR934x has proper SRAM.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Wills Wang <wills.wang@live.com>
diff --git a/arch/mips/mach-ath79/ar934x/cpu.c b/arch/mips/mach-ath79/ar934x/cpu.c
new file mode 100644
index 0000000..8fcdf65
--- /dev/null
+++ b/arch/mips/mach-ath79/ar934x/cpu.c
@@ -0,0 +1,10 @@
+/*
+ * Copyright (C) 2016 Marek Vasut <marex@denx.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+
+/* The lowlevel_init() is not needed on AR934x */
+void lowlevel_init(void) {}