Add TERMINAL_CMD variable

Author: gsingh93

Diff for: Makefile

@@ -390,6 +390,11 @@ run: $(RUN_DEPS) | $(SHARED_DIR)
 ifeq ($(GDB),1)
 	@echo "$(ARCH) $(ACK)" > $(OUT_DIR)/.gdb
 	@echo "$(GREEN)Waiting for GDB, attach with \`scripts/gdb.sh\` $(NC)"
+
+ifdef TERMINAL_CMD
+	$(TERMINAL_CMD) $(SCRIPT_DIR)/gdb.sh
+endif
+
 endif
 	@echo ''
 	$(QEMU_BIN) $(QEMU_ARGS)