nios2: add gpio support to nios2-generic board

This patch adds gpio support of Altera PIO component to the
nios2-generic board. Though it drives only gpio_led at the
moment, it supports bidirectional port to control bit-banging
I2C, NAND flash busy status or button switches, etc.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Tested-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Scott McNutt <smcnutt@psyent.com>
diff --git a/include/configs/nios2-generic.h b/include/configs/nios2-generic.h
index e83e1e3..e4bf57b 100644
--- a/include/configs/nios2-generic.h
+++ b/include/configs/nios2-generic.h
@@ -63,10 +63,10 @@
  * STATUS LED
  */
 #define CONFIG_STATUS_LED		/* Enable status driver */
-#define CONFIG_EPLED			/* Enable LED PIO driver */
-#define CONFIG_SYS_LEDPIO_ADDR		LED_PIO_BASE
+#define CONFIG_GPIO_LED		/* Enable GPIO LED driver */
+#define CONFIG_GPIO			/* Enable GPIO driver */
 
-#define STATUS_LED_BIT			1	/* Bit-0 on PIO */
+#define STATUS_LED_BIT			0	/* Bit-0 on GPIO */
 #define STATUS_LED_STATE		1	/* Blinking */
 #define STATUS_LED_PERIOD	(500 / CONFIG_SYS_NIOS_TMRMS) /* 500 msec */