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/include/dwc3-uboot.h b/include/dwc3-uboot.h
index e08530e..bb0436c 100644
--- a/include/dwc3-uboot.h
+++ b/include/dwc3-uboot.h
@@ -44,7 +44,7 @@
 
 int dwc3_uboot_init(struct dwc3_device *dev);
 void dwc3_uboot_exit(int index);
-void dwc3_uboot_handle_interrupt(int index);
+void dwc3_uboot_handle_interrupt(struct udevice *dev);
 
 struct phy;
 #if CONFIG_IS_ENABLED(PHY) && CONFIG_IS_ENABLED(DM_USB)