atl1: remove EXPERIMENTAL label

Remove the EXPERIMENTAL label from the atl1 driver and change the vendor
name to include Attansic's successor, Atheros.  We'll leave Attansic in
the name since Attansic's PCI ID (1969) is encoded in the PCI config and
is what users encounter on their systems.

Signed-off-by: Jay Cliburn <jacliburn@bellsouth.net>
Signed-off-by: David S. Miller <davem@davemloft.net>