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/uaccess.h b/arch/xtensa/include/asm/uaccess.h
index 3fa526f..6e4bb3b 100644
--- a/arch/xtensa/include/asm/uaccess.h
+++ b/arch/xtensa/include/asm/uaccess.h
@@ -17,7 +17,9 @@
 #define _XTENSA_UACCESS_H
 
 #include <linux/errno.h>
+#ifndef __ASSEMBLY__
 #include <linux/prefetch.h>
+#endif
 #include <asm/types.h>
 
 #define VERIFY_READ    0