version.mk: ensure that %S is always populated with a subtarget identifier, fallback to "generic" if no subtarget exists

SVN-Revision: 33534

include/version.mk

@@ -40,4 +40,4 @@ VERSION_SED:=$(SED) 's,%U,$(VERSION_REPO),g' \
 	-e 's,%d,\L$(subst $(space),_,$(VERSION_DIST)),g' \
 	-e 's,%R,$(REVISION),g' \
 	-e 's,%T,$(BOARD),g' \
-	-e 's,%S,$(BOARD)$(if $(SUBTARGET),/$(SUBTARGET)),g' \
+	-e 's,%S,$(BOARD)/$(if $(SUBTARGET),$(SUBTARGET),generic),g' \