Use the kernel bitmap library for internal perf tools uses.

Signed-off-by: Frederic Weisbecker
Cc: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Mike Galbraith
Cc: Paul Mackerras
Cc: Steven Rostedt
LKML-Reference:
Signed-off-by: Ingo Molnar