Network IP configuration

By default, AIBOX-1684X has a dynamic IP set for ethernet port 0, and
a static IP set for ethernet port 1. These configurations are
implemented through the "/etc/netplan/01-netcfg.yaml" file in the
system.

   linaro@aibox-1684x:~$ cat /etc/netplan/01-netcfg.yaml
   network:
           version: 2
           renderer: networkd
           ethernets:
                   eth0:
                           dhcp4: yes
                           addresses: []
                           optional: yes
                           dhcp-identifier: mac
                   eth1:
                           dhcp4: no
                           addresses: [192.168.150.1/24]
                           optional: yes

Users can modify the network configuration by modifying the
"/etc/netplan/01-netcfg.yaml" file, for example:

Set ethernet port 0 to a static IP address: Refer to the original
setting of eth1 to change node eth0, change parameter dhcp4 to no, and
add the IP address to parameter addresses.

Set ethernet port 1 to a dynamic IP address: Refer to the original
setting of eth0 to change node eth1, change parameter dhcp4 to yes,
and remove the IP address in the parameter addresses.

After modifying the '/etc/netplan/01-netcfg.yaml' file, users can make
the Settings take effect immediately by executing the "sudo netplan
apply" command.