dt-bindings: soc: imx: fsl,imx-iomuxc-gpr: add imx6

Add compatibles used by different i.MX6 variants to the i.MX IOMUX
Controller GPR binding.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Link: https://lore.kernel.org/r/20240226212740.2019837-5-sre@kernel.org


Signed-off-by: Rob Herring <robh@kernel.org>