pinctrl: nomadik: use of_property_read_bool

Use of_property_read_bool to check for the existence of a property.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression e1,e2,x;
@@
-	if (of_get_property(e1,e2,NULL))
-		x = true;
-	else
-		x = false;
+	x = of_property_read_bool(e1,e2);
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/nomadik/pinctrl-nomadik.c

@@ -1110,10 +1110,8 @@ static int nmk_gpio_probe(struct platform_device *dev)
 		return PTR_ERR(nmk_chip);
 	}
 
-	if (of_get_property(np, "st,supports-sleepmode", NULL))
-		supports_sleepmode = true;
-	else
-		supports_sleepmode = false;
+	supports_sleepmode =
+		of_property_read_bool(np, "st,supports-sleepmode");
 
 	/* Correct platform device ID */
 	dev->id = nmk_chip->bank;