ath9k: remove useless ath9k driver version information

Versioning for ath9k is pointless we have kept it at 0.1
since the initial release so its meaningless. We put more emphasis
on kernel release or dated wireless-testing master tag
as per John's tagging.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>