target/loongarch: Fix query-cpu-model-expansion to reject props

target/loongarch: Fix query-cpu-model-expansion to reject props

query-cpu-model-expansion takes a CpuModelInfo argument.  The
loongarch version of the command silently ignores the argument's
member @props.  For instance,

    {"execute": "query-cpu-model-expansion", "arguments": {"type": "static", "model": {"name": "la464", "props": null}}}

and

    {"execute": "query-cpu-model-expansion", "arguments": {"type": "static", "model": {"name": "la464", "props": {"prop": null}}}}

succeed.

Add skeleton code for property processing that recognizes no
properties.  Now the two commands fail as they should:

    {"error": {"class": "GenericError", "desc": "Invalid parameter type for 'model.props', expected: object"}}

and

    {"error": {"class": "GenericError", "desc": "Parameter 'model.props.prop' is unexpected"}}

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240305145919.2186971-5-armbru@redhat.com>
[Drop #include now superfluous]