cxgb4: Make t4_get_tp_e2c_map static

Fix sparse warning:

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c:6216:14:
 warning: symbol 't4_get_tp_e2c_map' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -6213,7 +6213,7 @@ unsigned int t4_get_mps_bg_map(struct adapter *adapter, int pidx)
  *      @adapter: the adapter
  *      @pidx: the port index
  */
-unsigned int t4_get_tp_e2c_map(struct adapter *adapter, int pidx)
+static unsigned int t4_get_tp_e2c_map(struct adapter *adapter, int pidx)
 {
 	unsigned int nports;
 	u32 param, val = 0;