ARM: dts: imx6q-cm-fx6: Use the 'vpcie-supply' property
According to Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt,
the property for specifying the PCIe regulator is 'vpcie-supply', so
use the correct one.
Also fix the polarity of GPIO2_24 so that the regulator can operate
correctly.