ARM: dts: mvebu: introduce internal-regs node

Introduce a 'internal-regs' subnode, under which all devices are
moved. This is not really needed for now, but will be for the
mvebu-mbus driver. This generates a lot of code movement since it's
indenting by one more tab all the devices.  So it was a good
opportunity to fix all the bad indentation.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>