MIPS: Octeon: Fix platform bus probing

Commit 44a7185c2ae6 ("of/platform: Add common method to populate
default bus") added new arch_initcall of_platform_default_populate_init()
that will override device_initcall octeon_publish_devices(). This broke
many OCTEON boards as important devices are not getting probed anymore
(e.g. on EdgeRouter Lite the USB mass storage/rootfs is missing).

Fix by changing octeon_publish_devices() to arch_initcall.

Fixes: 44a7185c2ae6 ("of/platform: Add common method to populate default bus")
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Rob Herring <robh@kernel.org>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14041/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>