ARM: dts: rockchip: add missing model properties

A test with the command below gives these errors:

arch/arm/boot/dts/rk3288-evb-act8846.dt.yaml: /: 'model'
is a required property
arch/arm/boot/dts/rk3288-evb-rk808.dt.yaml: /: 'model'
is a required property
arch/arm/boot/dts/rk3288-r89.dt.yaml: /: 'model'
is a required property

Fix this error by adding the missing model properties to
the involved dts files.

make ARCH=arm dtbs_check
DT_SCHEMA_FILES=~/.local/lib/python3.5/site-packages/dtschema/
schemas/root-node.yaml
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Link: https://lore.kernel.org/r/20200304074051.8742-1-jbx6244@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm/boot/dts/rk3288-evb-act8846.dts

@@ -4,6 +4,7 @@
 #include "rk3288-evb.dtsi"
 
 / {
+	model = "Rockchip RK3288 EVB ACT8846";
 	compatible = "rockchip,rk3288-evb-act8846", "rockchip,rk3288";
 
 	vcc_lcd: vcc-lcd {

arch/arm/boot/dts/rk3288-evb-rk808.dts

@@ -4,6 +4,7 @@
 #include "rk3288-evb.dtsi"
 
 / {
+	model = "Rockchip RK3288 EVB RK808";
 	compatible = "rockchip,rk3288-evb-rk808", "rockchip,rk3288";
 };
 

arch/arm/boot/dts/rk3288-r89.dts

@@ -9,6 +9,7 @@
 #include "rk3288.dtsi"
 
 / {
+	model = "Netxeon R89";
 	compatible = "netxeon,r89", "rockchip,rk3288";
 
 	memory@0 {