ARM: dts: mx53: Remove 'enable-active-low' property

'enable-active-low' is not a valid property for a GPIO controlled regulator.

According to Documentation/devicetree/bindings/regulator/gpio-regulator.txt:

"Optional properties:
...
- enable-active-high	: Polarity of GPIO is active high (default is low)."

,so the correct way to define an active-low GPIO controlled regulator is to
simply not pass 'enable-active-high'.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx53-tx53.dtsi

@@ -96,7 +96,6 @@
 			pinctrl-names = "default";
 			pinctrl-0 = <&pinctrl_can_xcvr>;
 			gpio = <&gpio4 21 GPIO_ACTIVE_HIGH>;
-			enable-active-low;
 		};
 
 		reg_usbh1_vbus: regulator@3 {