MIPS: lantiq: add xway soc ids

Add the soc ids for additional xway socs. The patch also merges the amazon_se
code with the other socs.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3707/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>