tegra2: Use new GPIO APIs in gpio_config_uart()

... rather than open-coding the register accesses.

However, gpio_request() typically stores the "label" parameter in a global
data structure. This causes problems when called from gpio_config_uart(),
since the code is running before relocation. To solve this, pass a NULL
string to gpio_request(), and modify gpio_request() not to touch the string
if it's NULL.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/drivers/gpio/tegra2_gpio.c b/drivers/gpio/tegra2_gpio.c
index f686e80..22669b6 100644
--- a/drivers/gpio/tegra2_gpio.c
+++ b/drivers/gpio/tegra2_gpio.c
@@ -146,8 +146,10 @@
 	if (gp >= MAX_NUM_GPIOS)
 		return -1;
 
-	strncpy(gpio_names[gp].name, label, GPIO_NAME_SIZE);
-	gpio_names[gp].name[GPIO_NAME_SIZE - 1] = '\0';
+	if (label != NULL) {
+		strncpy(gpio_names[gp].name, label, GPIO_NAME_SIZE);
+		gpio_names[gp].name[GPIO_NAME_SIZE - 1] = '\0';
+	}
 
 	/* Configure as a GPIO */
 	set_config(gp, 1);