ralink: add missing clk_set_rate()

Signed-off-by: John Crispin <blogic@openwrt.org>

SVN-Revision: 39896

target/linux/ramips/patches-3.10/999-clk.patch

+Index: linux-3.10.32/arch/mips/ralink/clk.c
+===================================================================
+--- linux-3.10.32.orig/arch/mips/ralink/clk.c	2014-03-12 03:04:05.468396764 +0000
++++ linux-3.10.32/arch/mips/ralink/clk.c	2014-03-12 03:29:00.220416177 +0000
+@@ -56,6 +56,12 @@
+ }
+ EXPORT_SYMBOL_GPL(clk_get_rate);
+ 
++int clk_set_rate(struct clk *clk, unsigned long rate)
++{
++	return -1;
++}
++EXPORT_SYMBOL_GPL(clk_set_rate);
++
+ void __init plat_time_init(void)
+ {
+ 	struct clk *clk;