arc: Add "model" properly in device tree description of all boards

As it was discussed quite some time ago (see
https://lkml.org/lkml/2015/11/5/862) it's a good practice to add
"model" property in .dts. Moreover as per ePAPR "model" property is
required and should look like "manufacturer,model" so we do here.

Signed-off-by: Alexey Brodkin <[e-mail]>
Cc: Vineet Gupta <[e-mail]>
Cc: Jonas Gorski <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>
Cc: Rob Herring <[e-mail]>
Cc: Christian Ruppert <[e-mail]>
Signed-off-by: Vineet Gupta <[e-mail]>

arch/arc/boot/dts/abilis_tb100_dvk.dts

···
 /include/ "abilis_tb100.dtsi"
 
 / {
+	model = "abilis,tb100";
 	chosen {
 		bootargs = "earlycon=uart8250,mmio32,0xff100000,9600n8 console=ttyS0,9600n8";
 	};

arch/arc/boot/dts/abilis_tb101_dvk.dts

···
 /include/ "abilis_tb101.dtsi"
 
 / {
+	model = "abilis,tb101";
 	chosen {
 		bootargs = "earlycon=uart8250,mmio32,0xff100000,9600n8 console=ttyS0,9600n8";
 	};

arch/arc/boot/dts/axs101.dts

···
 /include/ "axs10x_mb.dtsi"
 
 / {
+	model = "snps,axs101";
 	compatible = "snps,axs101", "snps,arc-sdp";
 
 	chosen {

arch/arc/boot/dts/axs103.dts

···
 /include/ "axs10x_mb.dtsi"
 
 / {
+	model = "snps,axs103";
 	compatible = "snps,axs103", "snps,arc-sdp";
 
 	chosen {

arch/arc/boot/dts/axs103_idu.dts

···
 /include/ "axs10x_mb.dtsi"
 
 / {
+	model = "snps,axs103-smp";
 	compatible = "snps,axs103", "snps,arc-sdp";
 
 	chosen {

arch/arc/boot/dts/nsim_700.dts

···
 /include/ "skeleton.dtsi"
 
 / {
+	model = "snps,nsim";
 	compatible = "snps,nsim";
 	#address-cells = <1>;
 	#size-cells = <1>;

arch/arc/boot/dts/nsim_hs.dts

···
 /include/ "skeleton_hs.dtsi"
 
 / {
+	model = "snps,nsim_hs";
 	compatible = "snps,nsim_hs";
 	#address-cells = <2>;
 	#size-cells = <2>;

arch/arc/boot/dts/nsim_hs_idu.dts

···
 /include/ "skeleton_hs_idu.dtsi"
 
 / {
+	model = "snps,nsim_hs-smp";
 	compatible = "snps,nsim_hs";
 	interrupt-parent = <&core_intc>;
 

arch/arc/boot/dts/nsimosci.dts

···
 /include/ "skeleton.dtsi"
 
 / {
+	model = "snps,nsimosci";
 	compatible = "snps,nsimosci";
 	#address-cells = <1>;
 	#size-cells = <1>;

arch/arc/boot/dts/nsimosci_hs.dts

···
 /include/ "skeleton_hs.dtsi"
 
 / {
+	model = "snps,nsimosci_hs";
 	compatible = "snps,nsimosci_hs";
 	#address-cells = <1>;
 	#size-cells = <1>;

arch/arc/boot/dts/nsimosci_hs_idu.dts

···
 /include/ "skeleton_hs_idu.dtsi"
 
 / {
+	model = "snps,nsimosci_hs-smp";
 	compatible = "snps,nsimosci_hs";
 	#address-cells = <1>;
 	#size-cells = <1>;

arch/arc/boot/dts/vdk_hs38.dts

···
 /include/ "vdk_axs10x_mb.dtsi"
 
 / {
+	model = "snps,vdk_archs";
 	compatible = "snps,axs103";
 
 	chosen {

arch/arc/boot/dts/vdk_hs38_smp.dts

···
 /include/ "vdk_axs10x_mb.dtsi"
 
 / {
+	model = "snps,vdk_archs-smp";
 	compatible = "snps,axs103";
 
 	chosen {