ixgbe: Make the bridge mode setting sticky

The internal bridge mode setting needs to be sticky so that it can be
configured correctly after a device reset.  This change is required now
that the driver supports setting the bridge mode to VEB or VEPA.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Tested-by: Sibai Li <Sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>