at91: redefine legacy GPIO PIN_BASE

In order to get the very same value for legacy pin definitions and new gpio
definitions set the legacy PIN_BASE to 0.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/arch/arm/include/asm/arch-at91/gpio.h b/arch/arm/include/asm/arch-at91/gpio.h
index b340afe..ff6142b 100644
--- a/arch/arm/include/asm/arch-at91/gpio.h
+++ b/arch/arm/include/asm/arch-at91/gpio.h
@@ -16,7 +16,7 @@
 
 #ifdef CONFIG_ATMEL_LEGACY
 
-#define PIN_BASE		32
+#define PIN_BASE		0
 
 #define MAX_GPIO_BANKS		5