tools: Add a toplevel Makefile

Add a Makefile with all the targets under tools/.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Sam Ravnborg <sam@ravnborg.org>
Link: http://lkml.kernel.org/r/1334162178-17152-4-git-send-email-bp@amd64.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>