net: marvell,prestera: Fix example PCI bus addressing

The example for PCI devices has some addressing errors. 'reg' is written
as if the parent bus is PCI, but the default bus for examples is 1
address and size cell. 'ranges' is defining config space with a
size of 0. Generally, config space should not be defined in
'ranges', only PCI memory and I/O spaces. Fix these issues by updating
the values with made-up, but valid values.

This was uncovered with recent dtschema changes.

Link: https://lore.kernel.org/r/20240122173514.935742-1-robh@kernel.org


Signed-off-by: Rob Herring <robh@kernel.org>