Generic A3720 mbox code is currently in Turris Mox specific board file
board/CZ.NIC/turris_mox/mox_sp.c. Move it to board independent arch file
arch/arm/mach-mvebu/armada3700/mbox.c.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
