i2c: switch from AT91 legacy to ATMEL legacy

Since the required API is gpio which is enclosed with CONFIG_ATMEL_LEGACY use
that switch here.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
Acked-by: Heiko Schocher <hs@denx.de>
diff --git a/drivers/i2c/soft_i2c.c b/drivers/i2c/soft_i2c.c
index 396fea8..dfea54a 100644
--- a/drivers/i2c/soft_i2c.c
+++ b/drivers/i2c/soft_i2c.c
@@ -25,7 +25,7 @@
 #include <asm/io.h>
 #include <asm/arch/hardware.h>
 #include <asm/arch/at91_pio.h>
-#ifdef CONFIG_AT91_LEGACY
+#ifdef CONFIG_ATMEL_LEGACY
 #include <asm/arch/gpio.h>
 #endif
 #endif