Drop an empty isicom.h from being exported to user space.

Drop <linux/isicom.h> from being exported to user space since it would
be only an empty file.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>