[PATCH] iseries_veth: Be consistent about driver name, increment version

The iseries_veth driver tells sysfs that it's called 'iseries_veth', but if
you ask it via ethtool it thinks it's called 'veth'. I think this comes from
2.4 when the driver was called 'veth', but it's definitely called
'iseries_veth' now, so fix it.

To make sure we don't do it again define DRV_NAME and use it everywhere.

While we're at it, change the version number to 2.0, to reflect the changes
made in this patch series.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>