headers_check fix: frv, swab.h

fix the following 'make headers_check' warning:

  usr/include/asm-frv/swab.h:4: include of <linux/types.h> is preferred over <asm/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

include/asm-frv/swab.h

 #ifndef _ASM_SWAB_H
 #define _ASM_SWAB_H
 
-#include <asm/types.h>
+#include <linux/types.h>
 
 #if defined(__GNUC__) && !defined(__STRICT_ANSI__) || defined(__KERNEL__)
 #  define __SWAB_64_THRU_32__