perf symbols: Add s390 idle functions 'psw_idle' and 'psw_idle_exit' to list of idle...

perf symbols: Add s390 idle functions 'psw_idle' and 'psw_idle_exit' to list of idle symbols

Add the s390 idle functions so they don't show up in top when using
software sampling.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Link: http://lore.kernel.org/lkml/20200707171457.85707-1-svens@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>