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/hsdk.dts b/arch/arc/dts/hsdk.dts
index 673bc5b..f024b96 100644
--- a/arch/arc/dts/hsdk.dts
+++ b/arch/arc/dts/hsdk.dts
@@ -8,6 +8,8 @@
 #include "dt-bindings/clock/snps,hsdk-cgu.h"
 
 / {
+	model = "snps,hsdk";
+
 	#address-cells = <1>;
 	#size-cells = <1>;