i40e: Prevent setting link speed on I40E_DEV_ID_25G_B

Setting link settings on backplane devices shouldn't be allowed.
This patch adds one more device id to the list which we check
that against.

Signed-off-by: Patryk Małek <patryk.malek@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>