cxgb4: Add TP Congestion map entry for single-port

Add TP Congestion Map entry for single-port T6 cards.
Signed-off-by: NCasey Leedom <leedom@chelsio.com>
Signed-off-by: NGanesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c

@@ -6091,6 +6091,7 @@ unsigned int t4_get_tp_ch_map(struct adapter *adap, int pidx)
 
 	case CHELSIO_T6:
 		switch (nports) {
+		case 1:
 		case 2: return 1 << pidx;
 		}
 		break;