Feature Request: Support Getting Ports of Specific Device Only

[thediveo]

At this time, Client.Ports lists all ports of all devices. Judging from, e.g. devlink_nl_dumpit, dumping ports supports the request attributes DEVLINK_ATTR_BUS_NAME and/or DEVLINK_ATTR_DEV_NAME.

Could you please support for example Client.PortsOfDevice(bus, device string) ([]*Port, error)?