usb: otg: support for multiple transceivers by a single controller

Add a linked list for keeping multiple PHY instances with different
types so that we can have separate USB2 and USB3 PHYs on one single
board. _get_phy_ has been changed so that the controller gets
the transceiver by type. _remove_phy_ has been added to let the phy
be removed from the phy list.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/pxa25x_udc.c b/drivers/usb/gadget/pxa25x_udc.c
index a658e44..cc0b1e6 100644
--- a/drivers/usb/gadget/pxa25x_udc.c
+++ b/drivers/usb/gadget/pxa25x_udc.c
@@ -2159,7 +2159,7 @@
 	dev->dev = &pdev->dev;
 	dev->mach = pdev->dev.platform_data;
 
-	dev->transceiver = usb_get_phy();
+	dev->transceiver = usb_get_phy(USB_PHY_TYPE_USB2);
 
 	if (gpio_is_valid(dev->mach->gpio_pullup)) {
 		if ((retval = gpio_request(dev->mach->gpio_pullup,