tools headers uapi: Sync linux/in.h copy from the kernel sources

To get the changes in this cset:

  65cab850 ("net: Allow class-e address assignment via ifconfig ioctl")

The macros changed in this cset are not used in tools/, so this is just
to silence this perf tools build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/in.h' differs from latest version at 'include/uapi/linux/in.h'
  diff -u tools/include/uapi/linux/in.h include/uapi/linux/in.h

Cc: Dave Taht <dave.taht@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-smghvyxb3budqd1e70i0ylw1@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>