[MIPS] Clocksource: Only install r4k counter as clocksource if present.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/time.h b/include/asm-mips/time.h
index a8fd16e..d3bd5c5 100644
--- a/include/asm-mips/time.h
+++ b/include/asm-mips/time.h
@@ -64,10 +64,11 @@
  * Initialize the count register as a clocksource
  */
 #ifdef CONFIG_CEVT_R4K
-extern void init_mips_clocksource(void);
+extern int init_mips_clocksource(void);
 #else
-static inline void init_mips_clocksource(void)
+static inline int init_mips_clocksource(void)
 {
+	return 0;
 }
 #endif