Optimizing tunnel configuration

Optimizing tunnel configuration

Description : Inorder to workaround some bug in ovsdb creating duplicate
tunnels, code was added in interface-manager to see if tunnel is getting
configured on a different DPN. Ideally this check is meant only for VM
migration where ports can migrate across DPNs. This check for tunnels is
resulting in scale issues when full mesh of tunnels is configured for
scaled setups. Since ovsdb bug is already fixed, removing this code
as it looks completely unnecessary.

Change-Id: I479a75890ac8d7e885fee54fef90fbc248d144e4
Signed-off-by: Faseela K <faseela.k@ericsson.com>