dm: usb: Pass EHCI controller pointer to ehci_set_usbmode()

Adjust this function so that it is passed an EHCI controller pointer so that
implementations can look up their controller. This makes the weak functions
use a consistent API.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c
index 17f8be1..0e6b60e 100644
--- a/drivers/usb/host/ehci-tegra.c
+++ b/drivers/usb/host/ehci-tegra.c
@@ -219,13 +219,12 @@
  * This ehci_set_usbmode overrides the weak function ehci_set_usbmode
  * in "ehci-hcd.c".
  */
-void ehci_set_usbmode(int index)
+void ehci_set_usbmode(struct ehci_ctrl *ctrl)
 {
-	struct fdt_usb *config;
+	struct fdt_usb *config = ctrl->priv;
 	struct usb_ctlr *usbctlr;
 	uint32_t tmp;
 
-	config = &port[index];
 	usbctlr = config->reg;
 
 	tmp = ehci_readl(&usbctlr->usb_mode);