headers_check fix: powerpc, spu_info.h

fix the following 'make headers_check' warning:

  usr/include/asm-powerpc/spu_info.h:27: found __[us]{8,16,32,64} type without #include <linux/types.h>

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>