usb: new board-specific USB init interface

This commit unifies board-specific USB initialization implementations
under one symbol (usb_board_init), declaration of which is available in
usb.h.

New API allows selective initialization of USB controllers whenever needed.

Signed-off-by: Mateusz Zalega <m.zalega@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Lukasz Majewski <l.majewski@samsung.com>
diff --git a/board/htkw/mcx/mcx.c b/board/htkw/mcx/mcx.c
index 653d7ea..6f85b47 100644
--- a/board/htkw/mcx/mcx.c
+++ b/board/htkw/mcx/mcx.c
@@ -42,7 +42,7 @@
 
 int ehci_hcd_init(int index, struct ehci_hccr **hccr, struct ehci_hcor **hcor)
 {
-	return omap_ehci_hcd_init(&usbhs_bdata, hccr, hcor);
+	return omap_ehci_hcd_init(index, &usbhs_bdata, hccr, hcor);
 }
 
 int ehci_hcd_stop(int index)