perf tools: Allow TSC conversion on any arch

It is possible to record a perf.data file on one architecture and
process it on another.

Consequently, TSC conversion functions need to be moved out of the arch
directory.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1405332185-4050-40-git-send-email-adrian.hunter@intel.com


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