fix the following 'make headers_check' warnings:

  usr/include/asm-avr32/swab.h:7: include of <linux/types.h> is preferred over <asm/types.h>
  usr/include/asm-avr32/swab.h:22: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>