beaglebone: move BBB-specific bits into a BBB config

Change-Id: If8551e362a15af83964a84a450f76293dc2b0cf0
diff --git a/board/czechlight/beaglebone/kconfig b/board/czechlight/beaglebone/kconfig
index 2871883..5dcd313 100644
--- a/board/czechlight/beaglebone/kconfig
+++ b/board/czechlight/beaglebone/kconfig
@@ -1 +1,5 @@
 CONFIG_OMAP_WATCHDOG=y
+
+# CONFIG_USB_ZERO is not set
+CONFIG_USB_CDC_COMPOSITE=m
+# CONFIG_USB_G_NOKIA is not set
diff --git a/board/czechlight/beaglebone/overlay/etc/systemd/system/network/30-usbnet-apipa.network b/board/czechlight/beaglebone/overlay/etc/systemd/system/network/30-usbnet-apipa.network
new file mode 100644
index 0000000..807dcc4
--- /dev/null
+++ b/board/czechlight/beaglebone/overlay/etc/systemd/system/network/30-usbnet-apipa.network
@@ -0,0 +1,6 @@
+[Match]
+Name=usb0
+
+[Network]
+Description=miniUSB console
+LinkLocalAddressing=yes