sunxi: gpio: Add temporary implementation of name_to_gpio()

Until sunxi moves to device tree (e.g. for USB) we need to convert named
GPIOs to numbers. Add a function to do this.

This fixes the USB / EHCI support not working on the LinkSprite pcDuino3
(which uses devicemodel).

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/gpio/sunxi_gpio.c

@@ -172,6 +172,17 @@ int sunxi_name_to_gpio(const char *name)
 #endif
 
 #ifdef CONFIG_DM_GPIO
+/* TODO(sjg@chromium.org): Remove this function and use device tree */
+int sunxi_name_to_gpio(const char *name)
+{
+	unsigned int gpio;
+	int ret;
+
+	ret = gpio_lookup_name(name, NULL, NULL, &gpio);
+
+	return ret ? ret : gpio;
+}
+
 static int sunxi_gpio_direction_input(struct udevice *dev, unsigned offset)
 {
 	struct sunxi_gpio_platdata *plat = dev_get_platdata(dev);