ifconfig: T2912: add helper to retrieve interface min/max supported MTU
ifconfig: T2912: add helper to retrieve interface min/max supported MTU

  >>> from vyos.ifconfig import Interface
  >>> tmp=Interface('eth0')
  >>> tmp.get_min_mtu()
  60
  >>> tmp.get_max_mtu()
  9000

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x