tools headers: Synchronize perf_event.h header

tools headers: Synchronize perf_event.h header

To get the changes in the 085b30625e39 ("perf/core: Add
PERF_AUX_FLAG_COLLISION to report colliding samples") commit, that will
be eventually used by perf to handle the ARM SPE architecture.

Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>