Update the tcp_server example to use the correct ip input callback.

Use tcpip_input() as the network interface function, it's required when
using a kernel.
Change the IP address shown into a string and add a comment.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4921 38d2e660-2303-0410-9eaa-f027e97ec537