usb: ehci-generic: Use regulator_set_enable_if_allowed

With the commit 4fcba5d5 ("regulator: implement basic reference
counter") the return value of regulator_set_enable may be EALREADY or
EBUSY for fixed/gpio regulators.

Change to use the more relaxed regulator_set_enable_if_allowed to
continue if regulator already was enabled or disabled.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Marek Vasut <marex@denx.de>

drivers/usb/host/ehci-generic.c

@@ -39,14 +39,10 @@ static int ehci_enable_vbus_supply(struct udevice *dev)
 	if (ret && ret != -ENOENT)
 		return ret;
 
-	if (priv->vbus_supply) {
-		ret = regulator_set_enable(priv->vbus_supply, true);
-		if (ret) {
-			dev_err(dev, "Error enabling VBUS supply (ret=%d)\n", ret);
-			return ret;
-		}
-	} else {
-		dev_dbg(dev, "No vbus supply\n");
+	ret = regulator_set_enable_if_allowed(priv->vbus_supply, true);
+	if (ret && ret != -ENOSYS) {
+		dev_err(dev, "Error enabling VBUS supply (ret=%d)\n", ret);
+		return ret;
 	}
 
 	return 0;
@@ -54,10 +50,13 @@ static int ehci_enable_vbus_supply(struct udevice *dev)
 
 static int ehci_disable_vbus_supply(struct generic_ehci *priv)
 {
-	if (priv->vbus_supply)
-		return regulator_set_enable(priv->vbus_supply, false);
-	else
-		return 0;
+	int ret;
+
+	ret = regulator_set_enable_if_allowed(priv->vbus_supply, false);
+	if (ret && ret != -ENOSYS)
+		return ret;
+
+	return 0;
 }
 
 static int ehci_usb_probe(struct udevice *dev)