atl1: relocate atl1 driver to /drivers/net/atlx

In preparation for a future Atheros L2 NIC driver (called atl2), relocate
the atl1 driver into a new /drivers/net/atlx directory that will ultimately
be shared with the future atl2 driver.

Signed-off-by: Chris Snook <csnook@redhat.com>
Signed-off-by: Jay Cliburn <jacliburn@bellsouth.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>