Fix cleanup target

Signed-off-by: Tomasz Michalak <tmichalak@antmicro.com>

Makefile_test.common

diff --git a/Makefile_test.common b/Makefile_test.common
index a2a3509..ae874eb 100644
--- a/Makefile_test.common
+++ b/Makefile_test.common
@@ -84,6 +84,6 @@
 $(foreach test,$(UNIT_TESTS),$(eval $(call unit_test_tpl,$(test))))
 
 clean:
-	@rm -rf $(foreach test,$(TESTS),$(test)/$(test).sdc $(test)/$(test).txt $(test)/$(test).eblif $(test)/$(test).json)
+	@rm -rf $(foreach test,$(TESTS),$(test)/$(test).sdc $(test)/$(test)_[0-9].sdc $(test)/$(test).txt $(test)/$(test).eblif $(test)/$(test).json)
 	@rm -rf $(foreach test,$(UNIT_TESTS),$(test)/$(test).test.o $(test)/$(test).test.d $(test)/$(test).test)
 	@find . -name "ok" -or -name "*.log" | xargs rm -rf