arm64: dts: freescale: add 'chassis-type' property

A new 'chassis-type' root node property has recently been approved for
the device-tree specification, in order to provide a simple way for
userspace to detect the device form factor and adjust their behavior
accordingly.

This patch fills in this property for end-user devices (such as laptops,
smartphones and tablets) based on NXP ARM64 processors.
Signed-off-by: NArnaud Ferraris <arnaud.ferraris@collabora.com>
Reviewed-by: NGuido Günther <agx@sigxcpu.org>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi

@@ -14,6 +14,7 @@
 / {
 	model = "Purism Librem 5";
 	compatible = "purism,librem5", "fsl,imx8mq";
+	chassis-type = "handset";
 
 	backlight_dsi: backlight-dsi {
 		compatible = "led-backlight";

arch/arm64/boot/dts/freescale/imx8mq-mnt-reform2.dts

@@ -12,6 +12,7 @@
 / {
 	model = "MNT Reform 2";
 	compatible = "mntre,reform2", "boundary,imx8mq-nitrogen8m-som", "fsl,imx8mq";
+	chassis-type = "laptop";
 
 	pcie1_refclk: clock-pcie1-refclk {
 		compatible = "fixed-clock";