{hmp, hw/pvrdma}: Expose device internals via monitor interface

{hmp, hw/pvrdma}: Expose device internals via monitor interface

Allow interrogating device internals through HMP interface.
The exposed indicators can be used for troubleshooting by developers or
sysadmin.
There is no need to expose these attributes to a management system (e.x.
libvirt) because (1) most of them are not "device-management' related
info and (2) there is no guarantee the interface is stable.

Signed-off-by: Yuval Shaia <yuval.shaia@oracle.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1552300155-25216-6-git-send-email-yuval.shaia@oracle.com>
Reviewed-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>