lantiq: xrx200: convert FritzBox 7360v2's wifi to nvmem

lantiq: xrx200: convert FritzBox 7360v2's wifi to nvmem

this was thoroughly tested (warm and cold boots). on a
real 7360v2. This is because there have been documented
hick-ups with other lantiq devices that need the
owl-loader too.

It's likely that the 7360(sl) could be converted in the
same way as well. However the 7362sl uses a reversed
caldata format, so the "qca,no-eeprom" stays in place.

The patch also moves the urloader nvmem partition
definition into the partition section.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>