Add support for Iomega Storcenter ix4-200d

Ok, that’s a start, but it looks like the ix2 dts doesn’t bring up the Ethernet interface.

You will need to create your own image using the custom ix4 dts I linked above.

Openwrt has good instructions on the wiki for building images. To make it super easy you could just replace the contents ix2 dts with the ix4 dts and build a hacked ix2 image.