tools include arch: Grab a copy of errno.h for arch's supported by perf

For each arch in tools/perf/arch, grab a copy of errno.h.

This is a pre-req to generate an architecture specific mapping of errno
numbers to their names. This errno mapping can be used by perf trace to
support cross-architecture trace reports and to get rid of the
audit-libs dependency.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: linux-s390@vger.kernel.org
LPU-Reference: 1516352177-11106-2-git-send-email-brueckner@linux.vnet.ibm.com
Link: https://lkml.kernel.org/n/tip-73azjhrzpjsskwi129020i2u@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>