bnxt: Move GENEVE support from hard-coded port to using port notifier

The port number for GENEVE is hard coded into the bnxt driver.  This is the
kind of thing we want to avoid going forward.  For now I will integrate
this back into the port notifier so that we can change the GENEVE port
number if we need to in the future.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Acked-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>