ipg: Remove device claimed by dl2k from pci id table

This patch removes D-Link DGE-550T PCI ID (1186:4000) from the ipg
driver. The ipg driver is for IP2000-based cards and the DGE-550T is
a DL2000-based card. The driver loads and works for a few moments, but
once a real workload is applied it stops operating. The ipg driver
claimed this ID since it was introduced in 2.6.24 and it's forced many
users to blacklist it.

The correct driver for this hardware is the dl2k driver, which has been
claiming this PCI ID since the 2.4 days.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>