drivers: ddr: main.c: Fix Bad Shift operator issue

Fix Bad Shift operator issue in step_to_string function
by adding an if check

Signed-off-by: Priyanka Singh <priyanka.singh@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/drivers/ddr/fsl/main.c b/drivers/ddr/fsl/main.c
index 8e14716..f389e5e 100644
--- a/drivers/ddr/fsl/main.c
+++ b/drivers/ddr/fsl/main.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright 2008-2014 Freescale Semiconductor, Inc.
+ * Copyright 2021 NXP
  */
 
 /*
@@ -297,9 +298,13 @@
 
 	unsigned int s = __ilog2(step);
 
-	if ((1 << s) != step)
-		return step_string_tbl[7];
-
+	if (s <= 31) {
+		if ((1 << s) != step)
+			return step_string_tbl[7];
+	} else {
+		if ((1 << (s - 32)) != step)
+			return step_string_tbl[7];
+	}
 	if (s >= ARRAY_SIZE(step_string_tbl)) {
 		printf("Error for the step in %s\n", __func__);
 		s = 0;