board: usb: Replace legacy usb_gadget_handle_interrupts()

The usb_gadget_handle_interrupts() is no longer used anywhere,
replace the remaining uses with dm_usb_gadget_handle_interrupts()
which takes udevice as a parameter.

Some of the UDC drivers currently ignore the index parameter altogether,
those also ignore the udevice and have to be reworked. Other like the
dwc3_uboot_handle_interrupt() had to be switched from index to udevice
look up to avoid breakage.

Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Tested-by: Mattijs Korpershoek <mkorpershoek@baylibre.com> # on khadas vim3
Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/board/ti/am43xx/board.c b/board/ti/am43xx/board.c
index 87e552a..58bfe7c 100644
--- a/board/ti/am43xx/board.c
+++ b/board/ti/am43xx/board.c
@@ -760,13 +760,13 @@
 	.index = 1,
 };
 
-int usb_gadget_handle_interrupts(int index)
+int dm_usb_gadget_handle_interrupts(struct udevice *dev)
 {
 	u32 status;
 
-	status = dwc3_omap_uboot_interrupt_status(index);
+	status = dwc3_omap_uboot_interrupt_status(dev);
 	if (status)
-		dwc3_uboot_handle_interrupt(index);
+		dwc3_uboot_handle_interrupt(dev);
 
 	return 0;
 }