perf target: Split out perf_target handling code

For further work on perf_target, it'd be better off splitting the code
into a separate file.

Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1335417327-11796-9-git-send-email-namhyung.kim@lge.com
[ committer note: Fixed perl build by using stdbool and types.h in target.h ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>