ARM: dts: am571x-idk: Fix GPIO polarity for MMC1 card detect

The GPIO polarity for MMC1 card detect is set to '0' which means
active-high. However the polarity should be active-low. Fix it
here.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am571x-idk.dts

@@ -68,7 +68,7 @@ &mmc1 {
 	status = "okay";
 	vmmc-supply = <&ldo1_reg>;
 	bus-width = <4>;
-	cd-gpios = <&gpio6 27 0>; /* gpio 219 */
+	cd-gpios = <&gpio6 27 GPIO_ACTIVE_LOW>; /* gpio 219 */
 };
 
 &omap_dwc3_2 {