Move debugfs.* to api/fs/. We have a common tools/lib/api/ place where
the Makefile lives and then we place the headers in subdirs.

For example, all the fs-related stuff goes to tools/lib/api/fs/ from
which we get libapikfs.a (acme got almost the naming he wanted :-)) and
we link it into the tools which need it - in this case perf and
tools/vm/page-types.

acme:

"Looking at the implementation, I think some tools can even link
directly to the .o files, avoiding the .a file altogether.

But that is just an optimization/finer granularity tools/lib/
cherrypicking that toolers can make use of."

Fixup documentation cleaning target while at it.

Signed-off-by: Borislav Petkov
Acked-by: Ingo Molnar
Cc: Adrian Hunter
Cc: Andi Kleen
Cc: Arjan van de Ven
Cc: David Ahern
Cc: Frederic Weisbecker
Cc: Ingo Molnar
Cc: Jiri Olsa
Cc: Mike Galbraith
Cc: Namhyung Kim
Cc: Paul Mackerras
Cc: Pekka Enberg
Cc: Peter Zijlstra
Cc: Robert Richter
Cc: Stanislav Fomichev
Cc: Stephane Eranian
Cc: Steven Rostedt
Link: http://lkml.kernel.org/r/1386605664-24041-2-git-send-email-bp@alien8.de
Signed-off-by: Arnaldo Carvalho de Melo