HID: export headers properly

I have people whining about using these headers in userspace, and they have
__KERNEL__ markings which implies they're supposed to be exported.  I also
added the required linux/types.h include to hidraw.h since it uses the __u##
kernel types.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Jiri Kosina <jikos@jikos.cz>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>