MIPS: parse chosen node on boot

Call early_init_devtree from inside __dt_setup_arch to allow parsing of the
chosen node.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3718/


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