Currently we have a global timeout for all network cards in the BOOTP/DHCP discovery process. Make this timeout a per-interface one, so better accommodate the upcoming 4-way DHCP handshake and to also cover the lease time limit a DHCP offer will come with. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>