Add 'throttle-bps' and 'throttle-ops' limitation to set QoS. The
two arguments work with both QEMU command line and QMP command.

Example of QEMU command line:
-object cryptodev-backend-builtin,id=cryptodev1,throttle-bps=1600,\
throttle-ops=100

Example of QMP command:
virsh qemu-monitor-command buster --hmp qom-set /objects/cryptodev1 \
throttle-ops 100

or cancel limitation:
virsh qemu-monitor-command buster --hmp qom-set /objects/cryptodev1 \
throttle-ops 0

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230301105847.253084-11-pizhenwei@bytedance.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>