usb: xhci: plat: Add USB 3.0 phy support

For Realtek SoC, the usb xhci uses different driver for u2phy and u3phy.
Therefore, add a hook to retrieve the USB 3.0 PHY to XHCI plat.
Signed-off-by: Stanley Chang <stanley_chang@realtek.com>
Link: https://lore.kernel.org/r/20230407060731.20537-1-stanley_chang@realtek.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-plat.c

@@ -291,6 +291,21 @@ int xhci_plat_probe(struct platform_device *pdev, struct device *sysdev, const s
 			goto dealloc_usb2_hcd;
 		}
 
+		xhci->shared_hcd->usb_phy = devm_usb_get_phy_by_phandle(sysdev,
+			    "usb-phy", 1);
+		if (IS_ERR(xhci->shared_hcd->usb_phy)) {
+			if (PTR_ERR(xhci->shared_hcd->usb_phy) != -ENODEV)
+				dev_err(sysdev, "%s get usb3phy fail (ret=%d)\n",
+					     __func__,
+					    (int)PTR_ERR(xhci->shared_hcd->usb_phy));
+			xhci->shared_hcd->usb_phy = NULL;
+		} else {
+			ret = usb_phy_init(xhci->shared_hcd->usb_phy);
+			if (ret)
+				dev_err(sysdev, "%s init usb3phy fail (ret=%d)\n",
+					    __func__, ret);
+		}
+
 		xhci->shared_hcd->tpl_support = hcd->tpl_support;
 	}