ARM: dts: imx6qdl-sabresd: Pass the correct PCI reset polarity

The PCI reset GPIO is active low, so represent it with the
GPIO_ACTIVE_LOW flag.

Even though the imx6 PCI driver will not take the polarity into account
in this case, it is better to provide a correct description in device-tree.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-sabresd.dtsi

@@ -533,7 +533,7 @@
 &pcie {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_pcie>;
-	reset-gpio = <&gpio7 12 0>;
+	reset-gpio = <&gpio7 12 GPIO_ACTIVE_LOW>;
 	status = "okay";
 };