[ARM] 3364/1: [cleanup] warning fix - definitions for enable_hlt and disable_hlt

Patch from Ben Dooks

The enable_hlt and disable_hlt should be declared in
include/asm/setup.h. This fixes sparse errors from
arch/arm/kernel/process.c
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

include/asm-arm/system.h

@@ -415,6 +415,9 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
 	return ret;
 }
 
+extern void disable_hlt(void);
+extern void enable_hlt(void);
+
 #endif /* __ASSEMBLY__ */
 
 #define arch_align_stack(x) (x)