dt-bindings: net: dsa: lantiq, xrx200-gswip: Fix minor style fixes

* Use one compatible line per line in the documentation
* Remove SoC revision depended compatible lines, we can detect that in
  the driver
* Use lower case letters in hex addresses
* Fix the size of the address ranges in the example, this now matches
  the sizes used by the SoC. The old ones will also work, this just adds
  some empty address space.
* Change the reg size of the gphy-fw node

Fixes: 86ce2bc7 ("dt-bindings: net: dsa: Add lantiq, xrx200-gswip DT bindings")
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Cc: devicetree@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>