tools build: Add Makefile.include

To ease up build framework code setup for users.

More shared code will be added in the following patches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1443004442-32660-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/build/tests/ex/Makefile

@@ -3,7 +3,8 @@ export CC      := gcc
 export LD      := ld
 export AR      := ar
 
-build := -f $(srctree)/tools/build/Makefile.build dir=. obj
+include $(srctree)/tools/build/Makefile.include
+
 ex: ex-in.o libex-in.o
 	gcc -o $@ $^