tegra: seaboard: Remove unused CONFIG_UART_DISABLE_GPIO

This CONFIG is not used, so drop it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

include/configs/seaboard.h

@@ -27,9 +27,6 @@
 #define CONFIG_TEGRA_ENABLE_UARTD
 #define CONFIG_SYS_NS16550_COM1		NV_PA_APB_UARTD_BASE
 
-/* On Seaboard: GPIO_PI3 = Port I = 8, bit = 3 */
-#define CONFIG_UART_DISABLE_GPIO	GPIO_PI3
-
 #define CONFIG_MACH_TYPE		MACH_TYPE_SEABOARD
 
 /* I2C */