microblaze: Use asm generic cmpxchg.h for !SMP case

The whole implementation is done in asm-generic/cmpxchg.h file and there is
no reason to duplicate it.
Also do not include asm-generic/cmpxchg-local.h because it is already
included from asm-generic/cmpxchg.h
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Stefan Asserhall <stefan.asserhall@xilinx.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

arch/microblaze/include/asm/cmpxchg.h

@@ -2,42 +2,8 @@
 #ifndef _ASM_MICROBLAZE_CMPXCHG_H
 #define _ASM_MICROBLAZE_CMPXCHG_H
 
-#include <linux/irqflags.h>
-
-void __bad_xchg(volatile void *ptr, int size);
-
-static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
-								int size)
-{
-	unsigned long ret;
-	unsigned long flags;
-
-	switch (size) {
-	case 1:
-		local_irq_save(flags);
-		ret = *(volatile unsigned char *)ptr;
-		*(volatile unsigned char *)ptr = x;
-		local_irq_restore(flags);
-		break;
-
-	case 4:
-		local_irq_save(flags);
-		ret = *(volatile unsigned long *)ptr;
-		*(volatile unsigned long *)ptr = x;
-		local_irq_restore(flags);
-		break;
-	default:
-		__bad_xchg(ptr, size), ret = 0;
-		break;
-	}
-
-	return ret;
-}
-
-#define xchg(ptr, x) \
-	((__typeof__(*(ptr))) __xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
-
-#include <asm-generic/cmpxchg.h>
-#include <asm-generic/cmpxchg-local.h>
+#ifndef CONFIG_SMP
+# include <asm-generic/cmpxchg.h>
+#endif
 
 #endif /* _ASM_MICROBLAZE_CMPXCHG_H */