tegra: colibri_t30: asix usb ethernet reset regression

Fix ASIX USB to Ethernet reset which due to the new driver model Tegra
GPIO driver changes now requires a label string to be provided
otherwise the reservation and subsequent direction/value calls will
fail.

This fixes a regression introduced by commit:

2fccd2d96badcdf6165658a99771a4c475586279
tegra: Convert tegra GPIO driver to use driver model

Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/board/toradex/colibri_t30/colibri_t30.c b/board/toradex/colibri_t30/colibri_t30.c
index ed043f4..f4bc7d8 100644
--- a/board/toradex/colibri_t30/colibri_t30.c
+++ b/board/toradex/colibri_t30/colibri_t30.c
@@ -35,7 +35,7 @@
 void pin_mux_usb(void)
 {
 	/* Reset ASIX using LAN_RESET */
-	gpio_request(GPIO_PDD0, NULL);
+	gpio_request(GPIO_PDD0, "LAN_RESET");
 	gpio_direction_output(GPIO_PDD0, 0);
 	udelay(5);
 	gpio_set_value(GPIO_PDD0, 1);