qemu-options: document memory-backend-ram

The documentation should mention -object memory-backend-ram.

Suggested-by: Yumei Huang <yuhuang@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20171128161529.3025-3-stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
1 file changed