MIPS: BCM63XX: Call board_register_device from device_initcall()

Some device registration (eg leds), expect subsystem initcall to be
run first, so move board device registration to device_initcall().

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2891/


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