libperf: Add gitignore

Ignore files that are generated by libperf and libperf tests.

Signed-off-by: Charlie Jenkins <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: https://lore.kernel.org/lkml/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/lib/perf/.gitignore

···
+# SPDX-License-Identifier: GPL-2.0-only
+libperf.pc
+libperf.so.*
+tests-shared
+tests-static