Disintegrate asm/system.h for Xtensa

Disintegrate asm/system.h for Xtensa.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h
index 23592ef..b409893 100644
--- a/arch/xtensa/include/asm/atomic.h
+++ b/arch/xtensa/include/asm/atomic.h
@@ -18,7 +18,7 @@
 
 #ifdef __KERNEL__
 #include <asm/processor.h>
-#include <asm/system.h>
+#include <asm/cmpxchg.h>
 
 #define ATOMIC_INIT(i)	{ (i) }