MIPS: Idle: Consolidate all declarations in <asm/idle.h>.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/idle.c b/arch/mips/kernel/idle.c
index 1f85dda..985cc02 100644
--- a/arch/mips/kernel/idle.c
+++ b/arch/mips/kernel/idle.c
@@ -18,6 +18,7 @@
 #include <linux/sched.h>
 #include <asm/cpu.h>
 #include <asm/cpu-info.h>
+#include <asm/idle.h>
 #include <asm/mipsregs.h>
 
 /*
@@ -44,8 +45,6 @@
 	local_irq_enable();
 }
 
-extern void r4k_wait(void);
-
 /*
  * This variant is preferable as it allows testing need_resched and going to
  * sleep depending on the outcome atomically.  Unfortunately the "It is