ARC: HSDK: split HSDK and HSDK-4xD DTS

Split HSDK and HSDK-4xD device tree files so they can have
different model names.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/arch/arc/dts/Makefile b/arch/arc/dts/Makefile
index 4f1e463..515fe1f 100644
--- a/arch/arc/dts/Makefile
+++ b/arch/arc/dts/Makefile
@@ -5,7 +5,7 @@
 dtb-$(CONFIG_TARGET_NSIM) +=  nsim.dtb
 dtb-$(CONFIG_TARGET_TB100) +=  abilis_tb100.dtb
 dtb-$(CONFIG_TARGET_EMSDP) +=  emsdp.dtb
-dtb-$(CONFIG_TARGET_HSDK) +=  hsdk.dtb
+dtb-$(CONFIG_TARGET_HSDK) +=  hsdk.dtb hsdk-4xd.dtb
 dtb-$(CONFIG_TARGET_IOT_DEVKIT) +=  iot_devkit.dtb
 
 targets += $(dtb-y)