usb: host: ehci-tegra: request deferred probe when failing to get phy

The commit 1290a958 ("usb: phy: propagate __of_usb_find_phy()'s error on
failure") changed the condition to return -EPROBE_DEFER to host driver.
Originally the Tegra host driver depended on the returned -EPROBE_DEFER to
get the phy device later when booting. Now we have to do that explicitly.
Signed-off-by: Vince Hsu <vinceh@nvidia.com>
Tested-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-tegra.c

@@ -451,7 +451,7 @@ static int tegra_ehci_probe(struct platform_device *pdev)
 
 	u_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "nvidia,phy", 0);
 	if (IS_ERR(u_phy)) {
-		err = PTR_ERR(u_phy);
+		err = -EPROBE_DEFER;
 		goto cleanup_clk_en;
 	}
 	hcd->usb_phy = u_phy;