MIPS: Add new GIC clocksource.

Add new clocksource that uses the counter present on the MIPS
Global Interrupt Controller.

Signed-off-by: Steven J. Hill <sjhill@mips.com>
Patchwork: http://patchwork.linux-mips.org/patch/4681/
Signed-off-by: John Crispin <blogic@openwrt.org>

arch/mips/include/asm/time.h

@@ -75,7 +75,7 @@ extern int init_r4k_clocksource(void);
 
 static inline int init_mips_clocksource(void)
 {
-#ifdef CONFIG_CSRC_R4K
+#if defined(CONFIG_CSRC_R4K) && !defined(CONFIG_CSRC_GIC)
 	return init_r4k_clocksource();
 #else
 	return 0;