[Mgmt] Fix show mgmt-interface address CLI for DHCP

[praveen-ramamoorthi]

What I did

show management_interface address CLI doesn't display management address configured via DHCP.

How I did it

For DHCP Management IP , Get the IP details from kernel via ipintutil

How to verify it

The DHCP IP of eth0 will be displayed in show management_interface address output.

Previous command output (if the output of a command-line utility has changed)

Without Fix :
root@sonic:~#  show management_interface address
root@sonic:~#

New command output (if the output of a command-line utility has changed)

With Fix :
root@sonic:~#  show management_interface address
Management IP address = 10.208.140.130/24
root@sonic:~#