phy: sun4i-usb: add support for missing USB PHY index

The new Allwinner H6 SoC's USB2 PHY has two holes -- USB1 (which is a
3.0 port with dedicated PHY) and USB2 (which doesn't exist at all).

Add support for this kind of missing USB PHY index.
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/allwinner/phy-sun4i-usb.c

@@ -126,6 +126,7 @@ struct sun4i_usb_phy_cfg {
 	bool dedicated_clocks;
 	bool enable_pmu_unk1;
 	bool phy0_dual_route;
+	int missing_phys;
 };
 
 struct sun4i_usb_phy_data {
@@ -646,6 +647,9 @@ static struct phy *sun4i_usb_phy_xlate(struct device *dev,
 	if (args->args[0] >= data->cfg->num_phys)
 		return ERR_PTR(-ENODEV);
 
+	if (data->cfg->missing_phys & BIT(args->args[0]))
+		return ERR_PTR(-ENODEV);
+
 	return data->phys[args->args[0]].phy;
 }
 
@@ -741,6 +745,9 @@ static int sun4i_usb_phy_probe(struct platform_device *pdev)
 		struct sun4i_usb_phy *phy = data->phys + i;
 		char name[16];
 
+		if (data->cfg->missing_phys & BIT(i))
+			continue;
+
 		snprintf(name, sizeof(name), "usb%d_vbus", i);
 		phy->vbus = devm_regulator_get_optional(dev, name);
 		if (IS_ERR(phy->vbus)) {