Bug 8874 - Tunnel_ips of hardware_vtep is cleared when Open vSwitch process restarted...

Bug 8874 - Tunnel_ips of hardware_vtep is cleared when Open vSwitch process restarted in Open vSwitch HWVTEP Emulator

Issue:
  Tunnel_ips of hardware_vtep is cleared when Open vSwitch process
  restarted in Open vSwitch HWVTEP Emulator

Cause of this issue:
  After Open vSwitch process restarted, ODL attempts to acquire tunnel_ips
  from CONFIGURATION MD-SAL and set it to Physical Switch.
  As tunnel_ips is not set from ODL but is set by vtep-ctl command, it
  does not exist in CONFIGURATION MD-SAL.
  This caused an empty value is set to tunnel_ips for Physical Switch.

Fix:
  Let ODL to acquire tunnel_ips from OPERATIONAL MD-SAL after
  VTEP Emulator restarted.

Change-Id: I439ba08c813ede02f82592ca0051b19140f40db2
Signed-off-by: Ryousuke Masuhara <r-masuhara@zn.nes.jp.nec.com>