convert bridge creation to service

update to systemd config files so that the bridge will be up
when systemd-networkd is started.

Signed-off-by: Tan Shen Joon <shen.joon.tan@intel.com>
Reviewed-by: Jack Ren <jack.ren@intel.com>

devicemodel/samples/nuc/bridge.sh

@@ -1,53 +0,0 @@
-#!/bin/bash
-
-# Instructions to create systemd-networkd configuration files:
-
-if [ ! -e /etc/systemd/network ]; then
-    mkdir -p /etc/systemd/network
-
-    # /etc/systemd/network/acrn.network
-    cat <<EOF>/etc/systemd/network/acrn.network
-[Match]
-Name=e*
-
-[Network]
-Bridge=acrn-br0
-EOF
-
-
-    # /etc/systemd/network/acrn.netdev
-    cat <<EOF>/etc/systemd/network/acrn.netdev
-[NetDev]
-Name=acrn-br0
-Kind=bridge
-EOF
-
-    # /etc/systemd/network/eth.network
-    cat <<EOF>/etc/systemd/network/eth.network
-[Match]
-Name=acrn-br0
-
-[Network]
-DHCP=ipv4
-EOF
-
-    # need to mask 80-dhcp.network and 80-virtual.network
-    ln -s /dev/null /etc/systemd/network/80-dhcp.network
-    ln -s /dev/null /etc/systemd/network/80-virtual.network
-
-    # should get specifc list of taps
-    # /etc/systemd/network/acrn_tap0.netdev
-    cat <<EOF>/etc/systemd/network/acrn_tap0.netdev
-[NetDev]
-Name=acrn_tap0
-Kind=tap
-EOF
-
-    # restart systemd-network to create the devices
-    # and bind network address to the bridge
-    systemctl restart systemd-networkd
-fi
-
-# add tap device under the bridge
-ifconfig acrn_tap0 up
-brctl addif acrn-br0 acrn_tap0