net/tcp: add connection info to tcp_stream structure

net/tcp: add connection info to tcp_stream structure

Changes:
 * Avoid use net_server_ip in tcp code, use tcp_stream data instead
 * Ignore packets from other connections if connection already created.
   This prevents us from connection break caused by other tcp stream.

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Reviewed-by: Simon Glass <sjg@chromium.org>