Even though we were parsing some DHCP options sent by the server, so far
we are only using the BOOTP 2-way handshake, even when talking to a DHCP
server.
Change this by actually sending out DHCP DISCOVER packets instead of the
generic (mostly empty) BOOTP BOOTREQUEST packets.
A pure BOOTP server would ignore the extra DHCP options in the DISCOVER
packet and would just reply with a BOOTREPLY packet, which we also
handle in the code.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>