arm64: dts: imx8qm: add lsio ss support

The LSIO SS of MX8QM is exactly the same as MX8QXP. So we can fully
reuse the exist LSIO SS dtsi. Add <soc>-ss-lsio.dtsi with compatible
string updated according to imx8-ss-lsio.dtsi.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8qm-ss-lsio.dtsi

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2019-2020 NXP
+ *	Dong Aisheng <aisheng.dong@nxp.com>
+ */
+
+&lsio_gpio0 {
+	compatible = "fsl,imx8qm-gpio", "fsl,imx35-gpio";
+};
+
+&lsio_gpio1 {
+	compatible = "fsl,imx8qm-gpio", "fsl,imx35-gpio";
+};
+
+&lsio_gpio2 {
+	compatible = "fsl,imx8qm-gpio", "fsl,imx35-gpio";
+};
+
+&lsio_gpio3 {
+	compatible = "fsl,imx8qm-gpio", "fsl,imx35-gpio";
+};
+
+&lsio_gpio4 {
+	compatible = "fsl,imx8qm-gpio", "fsl,imx35-gpio";
+};
+
+&lsio_gpio5 {
+	compatible = "fsl,imx8qm-gpio", "fsl,imx35-gpio";
+};
+
+&lsio_gpio6 {
+	compatible = "fsl,imx8qm-gpio", "fsl,imx35-gpio";
+};
+
+&lsio_gpio7 {
+	compatible = "fsl,imx8qm-gpio", "fsl,imx35-gpio";
+};
+
+&lsio_mu0 {
+	compatible = "fsl,imx8-mu-scu", "fsl,imx8qm-mu", "fsl,imx6sx-mu";
+};
+
+&lsio_mu1 {
+	compatible = "fsl,imx8-mu-scu", "fsl,imx8qm-mu", "fsl,imx6sx-mu";
+};
+
+&lsio_mu2 {
+	compatible = "fsl,imx8-mu-scu", "fsl,imx8qm-mu", "fsl,imx6sx-mu";
+};
+
+&lsio_mu3 {
+	compatible = "fsl,imx8-mu-scu", "fsl,imx8qm-mu", "fsl,imx6sx-mu";
+};
+
+&lsio_mu4 {
+	compatible = "fsl,imx8-mu-scu", "fsl,imx8qm-mu", "fsl,imx6sx-mu";
+};
+
+&lsio_mu13 {
+	compatible = "fsl,imx8qm-mu", "fsl,imx6sx-mu";
+};