at91: Correct NAND ECC register access

This uses the wrote base register value. Fix it.

Signed-off-by: Andre Renaud <andre@designa-electronics.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andreas Bießmann <andreas@biessmann.org>
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 75e8307..debf933 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -24,9 +24,9 @@
 
 /* Register access macros */
 #define ecc_readl(add, reg)				\
-	readl(AT91_BASE_SYS + add + ATMEL_ECC_##reg)
+	readl(add + ATMEL_ECC_##reg)
 #define ecc_writel(add, reg, value)			\
-	writel((value), AT91_BASE_SYS + add + ATMEL_ECC_##reg)
+	writel((value), add + ATMEL_ECC_##reg)
 
 #include "atmel_nand_ecc.h"	/* Hardware ECC registers */