dt-bindings: reserved-memory: ramoops: Convert txt bindings to yaml

Convert ramoops driver to the YAML syntax.

Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://lore.kernel.org/r/20211017141700.61201-4-david@ixit.cz


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