ixgbe: remove device ID for unsupported device

The ixgbe driver was untested with device ID 8086:10c8 but still advertises
support.  Currently if this device is present in the system when the driver
is loaded, the system will panic.
Remove this device ID until full support can be tested with available
hardware.  This patch is necessary for 2.6.24, 2.6.25 and 2.6.26

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>