usb: phy: generic: allow multiples calls to usb_phy_generic_register()

it's now very easy to return a platform_device pointer
and have the caller pass it as argument when calling
usb_phy_generic_unregister().

Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/musb/tusb6010.c b/drivers/usb/musb/tusb6010.c
index e1da199..f38a8db 100644
--- a/drivers/usb/musb/tusb6010.c
+++ b/drivers/usb/musb/tusb6010.c
@@ -31,6 +31,7 @@
 struct tusb6010_glue {
 	struct device		*dev;
 	struct platform_device	*musb;
+	struct platform_device	*phy;
 };
 
 static void tusb_musb_set_vbus(struct musb *musb, int is_on);
@@ -1222,7 +1223,7 @@
 	struct tusb6010_glue		*glue = platform_get_drvdata(pdev);
 
 	platform_device_unregister(glue->musb);
-	usb_phy_generic_unregister();
+	usb_phy_generic_unregister(glue->phy);
 	kfree(glue);
 
 	return 0;