chg: easy printing of MAKE variables

Usage::
  make print-FLASHTOOL
  cd bootrom; make print-APP_CFLAGS
  cd client; make print-GCC_VERSION

armsrc/Makefile

@@ -159,5 +159,4 @@ help:
 	@echo Multi-OS Makefile, you are running on $(DETECTED_OS)
 	@echo Possible targets:
 	@echo +	all    - Build the full image $(OBJDIR)/fullimage.s19
-	@echo +	clean             - Clean $(OBJDIR)
-
+	@echo +	clean             - Clean $(OBJDIR)