usb: host: xhci-plat: add xhci_plat_start()

Some platforms (such as the Renesas R-Car) need to initialize some specific
registers after xhci driver calls usb_add_hcd() and before the driver calls
xhci_run(). So, this patch adds the xhci_plat_start() function.

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 39c3673..29d8adb 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -37,6 +37,11 @@
 	return xhci_gen_setup(hcd, xhci_plat_quirks);
 }
 
+static int xhci_plat_start(struct usb_hcd *hcd)
+{
+	return xhci_run(hcd);
+}
+
 static const struct hc_driver xhci_plat_xhci_driver = {
 	.description =		"xhci-hcd",
 	.product_desc =		"xHCI Host Controller",
@@ -52,7 +57,7 @@
 	 * basic lifecycle operations
 	 */
 	.reset =		xhci_plat_setup,
-	.start =		xhci_run,
+	.start =		xhci_plat_start,
 	.stop =			xhci_stop,
 	.shutdown =		xhci_shutdown,