perf scripts: Add --symbols option to handle specific symbols

perf scripts: Add --symbols option to handle specific symbols

Since perf script no longer only handle the trace points, we can add the
symbol filter option so that scripts can handle specified samples.

Signed-off-by: Feng Tang <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>