Fix copying netdevs on npu (sonic-net#60)

Author: tirupatihemanth

files/image_config/midplane-network/define-npu-specific-netdevs.sh

@@ -3,6 +3,6 @@
 set -e
 
 if /bin/bash /usr/local/bin/is-npu-or-dpu.sh -n; then
-    cp /usr/share/sonic/templates/bridge-midplane.netdev /etc/systemd/network/
-    cp /usr/share/sonic/templates/dummy-midplane.netdev /etc/systemd/network/
+    cp --remove-destination /usr/share/sonic/templates/bridge-midplane.netdev /etc/systemd/network/
+    cp --remove-destination /usr/share/sonic/templates/dummy-midplane.netdev /etc/systemd/network/
 fi