net: support being a TCP server to unblock TCP fastboot

net: support being a TCP server to unblock TCP fastboot

Make following changes to unblock TCP fastboot support:

1. Implement being a TCP server support
2. Introduce dedicated TCP traffic handler (get rid of UDP signature)
3. Ensure seq_num and ack_num are respected in net_send_tcp_packet
function (make sure existing wget_cmd code is reflected with the fix)

Signed-off-by: Dmitrii Merkurev <[email protected]>
Cc: Ying-Chun Liu (PaulLiu) <[email protected]>
Cc: Simon Glass <[email protected]>
Сс: Joe Hershberger <[email protected]>
Сс: Ramon Fried <[email protected]>
Reviewed-by: Ying-Chun Liu (PaulLiu) <[email protected]>
Reviewed-by: Simon Glass <[email protected]>
Reviewed-by: Ramon Fried <[email protected]>