ARC: Add model property to boards .dts

1. This way we sync with Linux kernel where we have model
   set for all ARC boards for quite some time, see [1]

2. Once we enable DISPLAY_BOARDINFO for ARC this info will
   be printed on boot givin some extra data-point about the board

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=618a9cd06dd471ac232f5b27325b24d26eba5571

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/arch/arc/dts/abilis_tb100.dts b/arch/arc/dts/abilis_tb100.dts
index de3e57d..19e45b9 100644
--- a/arch/arc/dts/abilis_tb100.dts
+++ b/arch/arc/dts/abilis_tb100.dts
@@ -7,6 +7,8 @@
 #include "skeleton.dtsi"
 
 / {
+	model = "abilis,tb100";
+
 	aliases {
 		console = &uart0;
 	};