perf trace: Allow passing parms to arg formatters

So that we can have generic formatters that act upon specific
parameters.

Start using them with a simple string table that assumes entries
will be indexes to a string table, like with the 'which' parm
for the set and getitimer syscalls

Cc: 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: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-r0dqhapr8j6150v1wctgg340@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>