net: dsa: yt921x: Set ageing_time_min/ageing_time_max

The ageing time is in 5s step, ranging from 1 step to 0xffff steps, so
add appropriate attributes.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20251129042137.3034032-1-mmyangfl@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: yangfl

drivers/net/dsa/yt921x.c

@@ -2855,6 +2855,8 @@ static int yt921x_mdio_probe(struct mdio_device *mdiodev)
 	ds->assisted_learning_on_cpu_port = true;
 	ds->priv = priv;
 	ds->ops = &yt921x_dsa_switch_ops;
+	ds->ageing_time_min = 1 * 5000;
+	ds->ageing_time_max = U16_MAX * 5000;
 	ds->phylink_mac_ops = &yt921x_phylink_mac_ops;
 	ds->num_ports = YT921X_PORT_NUM;