MIPS: clock.h: Remove declaration of cpu_wait.

Duplicate and has no business in this header file.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/clock.h

@@ -6,8 +6,6 @@
 #include <linux/seq_file.h>
 #include <linux/clk.h>
 
-extern void (*cpu_wait) (void);
-
 struct clk;
 
 struct clk_ops {