usb: ehci-omap: Fix deferred probe for phy handling

PHY model is being used on omap5 platforms even if port mode
is not OMAP_EHCI_PORT_MODE_PHY. So don't guess if PHY is required
or not based on PHY mode.

If PHY is provided in device tree, it must be required. So, if
devm_usb_get_phy_by_phandle() gives us an error code other
than -ENODEV (no PHY) then error out.

This fixes USB Ethernet on omap5-uevm if PHY happens to
probe after EHCI thus causing a -EPROBE_DEFER.

Cc: Johan Hovold <johan@kernel.org>
Cc: Ladislav Michl <ladis@linux-mips.org>
Reported-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-omap.c

@@ -159,11 +159,12 @@ static int ehci_hcd_omap_probe(struct platform_device *pdev)
 		/* get the PHY device */
 		phy = devm_usb_get_phy_by_phandle(dev, "phys", i);
 		if (IS_ERR(phy)) {
-			/* Don't bail out if PHY is not absolutely necessary */
-			if (pdata->port_mode[i] != OMAP_EHCI_PORT_MODE_PHY)
+			ret = PTR_ERR(phy);
+			if (ret == -ENODEV) { /* no PHY */
+				phy = NULL;
 				continue;
+			}
 
-			ret = PTR_ERR(phy);
 			if (ret != -EPROBE_DEFER)
 				dev_err(dev, "Can't get PHY for port %d: %d\n",
 					i, ret);