ARM: dts: imx28-tx28: 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/imx28-tx28.dts

@@ -91,7 +91,6 @@ reg_can_xcvr: regulator@4 {
 			regulator-min-microvolt = <3300000>;
 			regulator-max-microvolt = <3300000>;
 			gpio = <&gpio1 0 0>;
-			enable-active-low;
 			pinctrl-names = "default";
 			pinctrl-0 = <&tx28_flexcan_xcvr_pins>;
 		};