perf scripting python: Add perf_set_itrace_options()

Add perf_set_itrace_options() to the perf_trace_context module so that a
script can set the itrace options for a session if they have not been set
already.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210530192308.7382-10-adrian.hunter@intel.com


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