arc: enable CONFIG_ARC_DW2_UNWIND

target/arc/kernel/synopsys-hsdk

@@ -1,4 +1,5 @@
 CONFIG_ISA_ARCV2=y
 CONFIG_ARC_SOC_HSDK=y
 CONFIG_ARC_UBOOT_SUPPORT=y
+CONFIG_ARC_DBG=y
 CONFIG_ARC_DW2_UNWIND=y