natsemi: Support Aculab E1/T1 PMXc cPCI carrier cards

Aculab E1/T1 PMXc cPCI carrier card cards present a natsemi on the cPCI
bus with an oversized EEPROM using a direct MII<->MII connection with no
PHY.  This patch adds a new device table entry supporting these cards.

Signed-Off-By: Mark Brown <broonie@sirena.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>