defaults: usb_gadget: Run service as a dependency of UDC device unit

Fixes #69 (closed)

debian/librem5-base-defaults.usb_gadget.service

@@ -2,7 +2,7 @@
 Description=Librem 5 USB gadget mode
 # This line to make sure that services like sshd
 # drop connections before the network goes down
-PartOf=network.target
+Before=network.target
 
 [Service]
 Type=oneshot
@@ -15,4 +15,4 @@ StandardError=journal
 # The MAC address on the device end. Specify this to get stable DHCP assignments.
 # Environment="DEV_ADDR=66:77:88:99:aa:bb"
 [Install]
-WantedBy=multi-user.target
+WantedBy=sys-devices-platform-soc\x400-38100000.usb-udc-38100000.usb.device