include linux/types.h in if_fddi.h

include/linux/if_fddi.h is an exported header.
It uses __be16. Include linux/types.h to get this prototype.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>