Staging: ath6kl: remove empty files that mess with 'distclean'

These two .h files would get removed from the tree when doing
	make distclean

It turns out they are not needed at all, so just delete them which fixes
people's git trees when doing development.
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>