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/musb/blackfin.c b/drivers/usb/musb/blackfin.c
index 522a4a2..4529409 100644
--- a/drivers/usb/musb/blackfin.c
+++ b/drivers/usb/musb/blackfin.c
@@ -415,7 +415,7 @@
 	gpio_direction_output(musb->config->gpio_vrsel, 0);
 
 	usb_nop_xceiv_register();
-	musb->xceiv = usb_get_phy();
+	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
 	if (!musb->xceiv) {
 		gpio_free(musb->config->gpio_vrsel);
 		return -ENODEV;