arm64: dts: imx8mq: Mark iomuxc_gpr as i.MX6Q compatible

Mark iomuxc_gpr as compatible with "fsl,imx6q-iomuxc-gpr" in order for
to allow i.MX6 PCIe driver to use it.
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Leonard Crestez <leonard.crestez@nxp.com>
Cc: "A.s. Dong" <aisheng.dong@nxp.com>
Cc: Richard Zhu <hongxing.zhu@nxp.com>
Cc: linux-imx@nxp.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mq.dtsi

@@ -404,7 +404,7 @@ iomuxc: iomuxc@30330000 {
 			};
 
 			iomuxc_gpr: syscon@30340000 {
-				compatible = "fsl,imx8mq-iomuxc-gpr", "syscon";
+				compatible = "fsl,imx8mq-iomuxc-gpr", "fsl,imx6q-iomuxc-gpr", "syscon";
 				reg = <0x30340000 0x10000>;
 			};