perf tools: Export normalize_arch() function

perf tools: Export normalize_arch() function

Export normalize_arch() function, so other part of perf can get
normalized form of arch string.

Signed-off-by: He Kuang <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Ekaterina Tumanova <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Sukadev Bhattiprolu <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>