usb: gadget: udc: at91: switch to using fwnode_gpiod_get_index()

I would like to stop exporting OF-specific gpiod_get_from_of_node()
so that gpiolib can be cleaned a bit, so let's switch to the generic
fwnode property API.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Link: https://lore.kernel.org/r/20220903-gpiod_get_from_of_node-remove-v1-5-b29adfb27a6c@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/at91_udc.c

@@ -1779,12 +1779,14 @@ static void at91udc_of_init(struct at91_udc *udc, struct device_node *np)
 	if (of_property_read_u32(np, "atmel,vbus-polled", &val) == 0)
 		board->vbus_polled = 1;
 
-	board->vbus_pin = gpiod_get_from_of_node(np, "atmel,vbus-gpio", 0,
-						 GPIOD_IN, "udc_vbus");
+	board->vbus_pin = fwnode_gpiod_get_index(of_fwnode_handle(np),
+						 "atmel,vbus", 0, GPIOD_IN,
+						 "udc_vbus");
 	if (IS_ERR(board->vbus_pin))
 		board->vbus_pin = NULL;
 
-	board->pullup_pin = gpiod_get_from_of_node(np, "atmel,pullup-gpio", 0,
+	board->pullup_pin = fwnode_gpiod_get_index(of_fwnode_handle(np),
+						   "atmel,pullup", 0,
 						   GPIOD_ASIS, "udc_pullup");
 	if (IS_ERR(board->pullup_pin))
 		board->pullup_pin = NULL;