tools headers UAPI: Sync linux/prctl.h with the kernel sources

  ddc65971 ("prctl: add PR_GET_AUXV to copy auxv to userspace")

To pick the changes in:

That don't result in any changes in tooling:

  $ tools/perf/trace/beauty/prctl_option.sh > before
  $ cp include/uapi/linux/prctl.h tools/include/uapi/linux/prctl.h
  $ tools/perf/trace/beauty/prctl_option.sh > after
  $ diff -u before after
  $

This actually adds a new prctl arg, but it has to be dealt with
differently, as it is not in sequence with the other arguments.

Just silences this perf tools build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/prctl.h' differs from latest version at 'include/uapi/linux/prctl.h'
  diff -u tools/include/uapi/linux/prctl.h include/uapi/linux/prctl.h
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/include/uapi/linux/prctl.h

@@ -290,6 +290,8 @@ struct prctl_mm_map {
 #define PR_SET_VMA		0x53564d41
 # define PR_SET_VMA_ANON_NAME		0
 
+#define PR_GET_AUXV			0x41555856
+
 #define PR_SET_MEMORY_MERGE		67
 #define PR_GET_MEMORY_MERGE		68
 #endif /* _LINUX_PRCTL_H */