i40: disable FCoE for MFP modes

Currently FCoE is not supported with MFP modes, so this patch
makes sure it is disabled.

It is disabled by overriding HW FCoE capability, so that later
it can be re-enabled by just the SW upgrade.

Change-ID: I1c0bae5c099b209f56b88bda360031a8565e43e8
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-By: Jack Morgan <jack.morgan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>