firstlogin: bring up wifi device before scanning

Scanning accesspoints requires an activated wifi device.
Networkd does not activate it (only NetworkManager does so).
As a result, firstlogin is not able to configure and use wifi on minimal
images, as only Server and Desktop images have NetworkManeger installed.
Activating the wifi device using "ip link set ${WIFI_DEVICE} up" before
scanning fixes this.
(And can safely be done - there is no problem activating it multiple
times, as it is the case with NetworkManager installed.)

packages/bsp/common/usr/lib/armbian/armbian-firstlogin

@@ -304,6 +304,8 @@ set_timezone_and_locales() {
 					WIFI_DEVICE=$(echo ${WIFI_DEVICES[$input-1]} | cut -d"," -f2)
 				fi
 
+				# bring up wifi device (not done by networkd, only by NetworkManager)
+				ip link set ${WIFI_DEVICE} up
 				# get list of wireless networks
 				scanning=0
 				broken=1