phy: rockchip-typec: fall back to working in host-mode if extcon is missing.

Right now the rockchip type-c phy does fail probing when no extcon is
detected. Some boards get the cable-state via the extcon interface and
have this supported, other boards seem to use the fusb302 chip or
another but the driver currently does not seem to utilize the extcon
interface to report the cable-state. And, other, just connect the type-c
to a standard USB-A port so use no controller at all. A missing extcon
shouldn't fail to probe, instead, should just fall back to working in
host-mode if it cannot get the extcon.

Fixes: c301b327aea898af ("arm64: dts: rockchip: add usb3-phy otg-port support for rk3399")
Reported-by: Vicente Bergas <[e-mail]>
Signed-off-by: Enric Balletbo i Serra <[e-mail]>
Reviewed-by: Heiko Stuebner <[e-mail]>
Signed-off-by: Kishon Vijay Abraham I <[e-mail]>

drivers/phy/rockchip/phy-rockchip-typec.c

···
 	u8 mode;
 	int ret;
 
+	if (!edev)
+		return MODE_DFP_USB;
+
 	ufp = extcon_get_state(edev, EXTCON_USB);
 	dp = extcon_get_state(edev, EXTCON_DISP_DP);
 
···
 
 	tcphy->extcon = extcon_get_edev_by_phandle(dev, 0);
 	if (IS_ERR(tcphy->extcon)) {
-		if (PTR_ERR(tcphy->extcon) != -EPROBE_DEFER)
-			dev_err(dev, "Invalid or missing extcon\n");
-		return PTR_ERR(tcphy->extcon);
+		if (PTR_ERR(tcphy->extcon) == -ENODEV) {
+			tcphy->extcon = NULL;
+		} else {
+			if (PTR_ERR(tcphy->extcon) != -EPROBE_DEFER)
+				dev_err(dev, "Invalid or missing extcon\n");
+			return PTR_ERR(tcphy->extcon);
+		}
 	}
 
 	pm_runtime_enable(dev);