mac_hwgrp_num
rgrpnum = mac_hwgrp_num(mh, MAC_RING_TYPE_RX);
tgrpnum = mac_hwgrp_num(mh, MAC_RING_TYPE_TX);
tgrpnum = mac_hwgrp_num(mh, MAC_RING_TYPE_TX);
extern uint_t mac_hwgrp_num(mac_handle_t, int);