dm: sunxi: Linksprite_pcDuino3: Correct polarity of MMC card detect

This is shown as active high in the schematics[1], so fix it.

[1] https://patchwork.ozlabs.org/patch/777890/

Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/dts/sun7i-a20-pcduino3.dts

@@ -164,7 +164,7 @@
 	pinctrl-0 = <&mmc0_pins_a>, <&mmc0_cd_pin_reference_design>;
 	vmmc-supply = <&reg_vcc3v3>;
 	bus-width = <4>;
-	cd-gpios = <&pio 7 1 GPIO_ACTIVE_HIGH>; /* PH1 */
+	cd-gpios = <&pio 7 1 GPIO_ACTIVE_LOW>; /* PH1 */
 	cd-inverted;
 	status = "okay";
 };