net: dm: fec: Fix regulator enable when using DM_REGULATOR

When DM_REGULATOR is enabled, the driver attempts to call
regulator_autoset() which expects the regulators to be on at boot
and/or always on and fails if they are not true.
For a more generic approach, this patch just calls
regulator_set_enable() which shouldn't have such restrictions.

Fixes: ad8c43cbca ("net: dm: fec: Support the phy-supply
binding")

Signed-off-by: Adam Ford <aford173@gmail.com>
Tested-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

drivers/net/fec_mxc.c

@@ -1348,7 +1348,7 @@ static int fecmxc_probe(struct udevice *dev)
 
 #ifdef CONFIG_DM_REGULATOR
 	if (priv->phy_supply) {
-		ret = regulator_autoset(priv->phy_supply);
+		ret = regulator_set_enable(priv->phy_supply, true);
 		if (ret) {
 			printf("%s: Error enabling phy supply\n", dev->name);
 			return ret;