mtd: nand: atmel: use another functions to set gpio value

Because there isn't the implementation of gpio_set/get_value()
and gpio_set/get_value() after the at91 gpio driver is converted
to support the driver model, use at91_set_gpio_value() and
at91_get_gpio_value()

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/mtd/nand/atmel_nand.c

@@ -1222,7 +1222,8 @@ static void at91_nand_hwcontrol(struct mtd_info *mtd,
 			IO_ADDR_W |= CONFIG_SYS_NAND_MASK_ALE;
 
 #ifdef CONFIG_SYS_NAND_ENABLE_PIN
-		gpio_set_value(CONFIG_SYS_NAND_ENABLE_PIN, !(ctrl & NAND_NCE));
+		at91_set_gpio_value(CONFIG_SYS_NAND_ENABLE_PIN,
+				    !(ctrl & NAND_NCE));
 #endif
 		this->IO_ADDR_W = (void *) IO_ADDR_W;
 	}
@@ -1234,7 +1235,7 @@ static void at91_nand_hwcontrol(struct mtd_info *mtd,
 #ifdef CONFIG_SYS_NAND_READY_PIN
 static int at91_nand_ready(struct mtd_info *mtd)
 {
-	return gpio_get_value(CONFIG_SYS_NAND_READY_PIN);
+	return at91_get_gpio_value(CONFIG_SYS_NAND_READY_PIN);
 }
 #endif