net: e1000: reject unsupported coalescing params

Set ethtool_ops->supported_coalesce_params to let
the core reject unsupported coalescing parameters.

This driver did not previously reject unsupported parameters.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/e1000/e1000_ethtool.c

@@ -1852,6 +1852,7 @@ static void e1000_get_strings(struct net_device *netdev, u32 stringset,
 }
 
 static const struct ethtool_ops e1000_ethtool_ops = {
+	.supported_coalesce_params = ETHTOOL_COALESCE_RX_USECS,
 	.get_drvinfo		= e1000_get_drvinfo,
 	.get_regs_len		= e1000_get_regs_len,
 	.get_regs		= e1000_get_regs,