perf cpumap: No need to include perf.h, ditch it

From a quick look this was never needed and just polluted the build,
needlessly making things including cpumap.h to be rebuild if perf.h or
anything it includes gets changed.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-x10p8slllqkn3fc3bntjx3n0@git.kernel.org


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