net/mvpp2: fix port speed overflow

[ upstream commit 8fa07a6 ]

ethtool_cmd_speed return uint32 and after the arithmetic
operation in mrvl_get_max_rate func the result is out of range.

Fixes: 429c394 ("net/mvpp2: support traffic manager")

Signed-off-by: Dana Vardi <danat@marvell.com>
Reviewed-by: Liron Himi <lironh@marvell.com>

drivers/net/mvpp2/mrvl_tm.c

@@ -57,7 +57,7 @@ mrvl_get_max_rate(struct rte_eth_dev *dev, uint64_t *rate)
 
 	close(fd);
 
-	*rate = ethtool_cmd_speed(&edata) * 1000 * 1000 / 8;
+	*rate = (uint64_t)ethtool_cmd_speed(&edata) * 1000 * 1000 / 8;
 
 	return 0;
 }