Wi-Fi: Add template finit service for wpa_supplicant

board/common/rootfs/etc/finit.d/available/wifi@.conf

@@ -0,0 +1,5 @@
+service name:wpa_supplicant :%i \
+			[2345] wpa_supplicant -s -i %i -c /etc/wpa_supplicant-%i.conf -P/var/run/wpa_supplicant-%i.pid \
+			       -- WPA supplicant @%i
+
+task name:wifi-scanner :%i [2345] <pid/wpa_supplicant:%i> /usr/libexec/infix/wifi-scanner %i -- Start scanning for SSID @ %i

board/common/rootfs/usr/libexec/infix/wifi-scanner

@@ -0,0 +1,16 @@
+#!/bin/sh
+
+if [ $# -ne 1 ]; then
+	echo "usage: $0 <ifname>"
+	exit 1
+fi
+ifname=$1
+
+TIMEOUT=300
+status=$(wpa_cli -i $ifname scan)
+while [ "$status" != "OK" ]; do
+	status=$(wpa_cli -i $ifname scan)
+	TIMEOUT=$((TIMEOUT-1))
+	[ $TIMEOUT -eq 0 ] && logger -t wifi-scanner "Failed to start scanning $ifname" && exit 1
+	sleep 0.5
+done