dt-bindings: gpio: fsl,qoriq-gpio: Add compatible string fsl,ls1046a-gpio

Add compatible string for chip ls1046 to fix below warning.
arch/arm64/boot/dts/freescale/fsl-ls1046a-frwy.dtb: /soc/gpio@2300000: failed to match any schema with compatible: ['fsl,ls1046a-gpio', 'fsl,qoriq-gpio']

Signed-off-by: Frank Li <[e-mail]>
Acked-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bartosz Golaszewski <[e-mail]>

Documentation/devicetree/bindings/gpio/fsl,qoriq-gpio.yaml

···
               - fsl,ls1021a-gpio
               - fsl,ls1028a-gpio
               - fsl,ls1043a-gpio
+              - fsl,ls1046a-gpio
               - fsl,ls1088a-gpio
               - fsl,ls2080a-gpio
           - const: fsl,qoriq-gpio