MX31: imx31_litekit: make use of GPIO framework

Signed-off-by: Stefano Babic <sbabic@denx.de>

include/configs/imx31_litekit.h

@@ -63,6 +63,7 @@
 
 #define CONFIG_MXC_UART	1
 #define CONFIG_SYS_MX31_UART1		1
+#define CONFIG_MXC_GPIO
 
 #define CONFIG_HARD_SPI		1
 #define CONFIG_MXC_SPI		1