usb: musb: move usb_phy_generic_{un,}register calls to probe()/remove()

This patch is in preparation to supporting
calling those functions multiple times.

Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/musb/am35x.c

@@ -360,7 +360,6 @@ static int am35x_musb_init(struct musb *musb)
 	if (!rev)
 		return -ENODEV;
 
-	usb_phy_generic_register();
 	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
 	if (IS_ERR_OR_NULL(musb->xceiv))
 		return -EPROBE_DEFER;
@@ -402,7 +401,6 @@ static int am35x_musb_exit(struct musb *musb)
 		data->set_phy_power(0);
 
 	usb_put_phy(musb->xceiv);
-	usb_phy_generic_unregister();
 
 	return 0;
 }
@@ -505,6 +503,7 @@ static int am35x_probe(struct platform_device *pdev)
 
 	pdata->platform_ops		= &am35x_ops;
 
+	usb_phy_generic_register();
 	platform_set_drvdata(pdev, glue);
 
 	pinfo = am35x_dev_info;
@@ -547,6 +546,7 @@ static int am35x_remove(struct platform_device *pdev)
 	struct am35x_glue	*glue = platform_get_drvdata(pdev);
 
 	platform_device_unregister(glue->musb);
+	usb_phy_generic_unregister();
 	clk_disable(glue->clk);
 	clk_disable(glue->phy_clk);
 	clk_put(glue->clk);