usb: host: ehci-vf: Implement board_usb_phy_mode weak function

Add board_usb_phy_mode weak function on similar lines to ehci-mx6.
However since Vybrid USB does not have a true OTG, make this weak
functon just return 0. The function is supposed to be implemented
by the individual boards using a GPIO for providing the OTG pin
functionality.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
diff --git a/drivers/usb/host/ehci-vf.c b/drivers/usb/host/ehci-vf.c
index 351e0fb..335e303 100644
--- a/drivers/usb/host/ehci-vf.c
+++ b/drivers/usb/host/ehci-vf.c
@@ -121,6 +121,11 @@
 	setbits_le32(ctrl, UCTRL_OVER_CUR_DIS);
 }
 
+int __weak board_usb_phy_mode(int port)
+{
+	return 0;
+}
+
 int __weak board_ehci_hcd_init(int port)
 {
 	return 0;
@@ -130,6 +135,7 @@
 		struct ehci_hccr **hccr, struct ehci_hcor **hcor)
 {
 	struct usb_ehci *ehci;
+	enum usb_init_type type;
 
 	if (index >= ARRAY_SIZE(nc_reg_bases))
 		return -EINVAL;
@@ -148,6 +154,10 @@
 	*hcor = (struct ehci_hcor *)((uint32_t)*hccr +
 			HC_LENGTH(ehci_readl(&(*hccr)->cr_capbase)));
 
+	type = board_usb_phy_mode(index);
+	if (type != init)
+		return -ENODEV;
+
 	if (init == USB_INIT_DEVICE) {
 		setbits_le32(&ehci->usbmode, CM_DEVICE);
 		writel((PORT_PTS_UTMI | PORT_PTS_PTW), &ehci->portsc);