tweak dhcp service example - add ntp configuration

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

examples/var_service/dhcp_if/convert2ntpconf

@@ -0,0 +1,34 @@
+#!/bin/sh
+# convert:
+
+# dhcptype=5
+# serverid=172.16.42.102
+# lease=97200
+# interface=eth0
+# ip=172.16.42.177
+# subnet=255.255.255.0
+# mask=24
+# broadcast=172.16.22.255
+# router=172.16.42.98
+# dns=10.34.32.125 10.32.63.5 10.34.255.7 10.11.255.27
+# domain=lab.example.com example.com
+# ntpsrv=10.34.32.125 10.34.255.7
+
+# into:
+
+#let cfg=cfg+1
+#ntpip[$cfg]=...
+
+exec >/dev/null
+#exec >"$0.out"  # debug
+exec 2>&1
+
+test "$interface" || exit 1
+test "$ip" || exit 1
+
+{
+for n in $ntpsrv; do
+	echo "let cfg=cfg+1"
+	echo "ntpip[\$cfg]='$n'";
+done
+} >"$1"