[ARM] 5400/1: Add support for inverted rdy_busy pin for Atmel nand device controller

Add support for inverted rdy_busy pin for Atmel nand device controller
It will fix building error on NeoCore926 board.

Acked-by: Andrew Victor <linux@maxim.org.za>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Gregory CLEMENT <gclement@adeneo.adetelgroup.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index c98c1570..47a33ce 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -139,7 +139,8 @@
 	struct nand_chip *nand_chip = mtd->priv;
 	struct atmel_nand_host *host = nand_chip->priv;
 
-	return gpio_get_value(host->board->rdy_pin);
+	return gpio_get_value(host->board->rdy_pin) ^
+                !!host->board->rdy_pin_active_low;
 }
 
 /*