arm: dts: calxeda: Basic DT file fixes

The .dts files for the Calxeda machines are quite old, so carry some
sloppy mistakes that the DT schema checker will complain about.

Fix those issues, they should not have any effect on functionality.

Link: https://lore.kernel.org/r/20200228135106.220620-2-andre.przywara@arm.com


Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>