tools headers uapi: Update tools's copy of linux/perf_event.h

To get the changes in:

  6cbc304f

 ("perf/x86/intel: Fix unwind errors from PEBS entries (mk-II)")

That do not imply any changes in the tooling side, the (ab)use of
sample_type is entirely done in kernel space, nothing for userspace to
witness here.

This cures the following warning during perf's build:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-o64mjoy35s9gd1gitunw1zg4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>