tools/perf/build: Make sure autodep feature binaries honor the O= setting

Arnaldo noticed that the feature-check binaries are generated in the
config/check-features/ directory even if O= is specified.

Implement $(OUTPUT) logic for config/check-features/Makefile.

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-NLwlnv5prsubuey0vfocebym@git.kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>