nitrogen6x: supply custom version of /etc/network/interfaces

Nitrogen6X/6_Max/6_Lite all use the nl80211 driver for wpa_supplicant
and none of them have an eth1 device.

Change-Id: I17a316d79a1d787229fd9acb758d993921e85dfb
Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@digia.com>

recipes/init-ifupdown/init-ifupdown/nitrogen6x/interfaces

+# /etc/network/interfaces -- configuration file for ifup(8), ifdown(8)
+ 
+# The loopback interface
+auto lo
+iface lo inet loopback
+
+# Wireless interfaces
+iface wlan0 inet dhcp
+	wireless_mode managed
+	wireless_essid any
+	wpa-driver nl80211
+	wpa-conf /etc/wpa_supplicant.conf
+
+iface atml0 inet dhcp
+
+# Wired or wireless interfaces
+auto eth0
+iface eth0 inet dhcp
+    hostname `/bin/hostname`
+
+# Ethernet/RNDIS gadget (g_ether)
+# ... or on host side, usbnet and random hwaddr
+iface usb0 inet static
+	address 192.168.7.2
+	netmask 255.255.255.0
+	network 192.168.7.0
+	gateway 192.168.7.1
+
+# Bluetooth networking
+iface bnep0 inet dhcp
+