perf tools: Build syscall table .c header from kernel's syscall_64.tbl

We used libaudit to map ids to syscall names and vice-versa, but that
imposes a delay in supporting new syscalls, having to wait for libaudit
to get those new syscalls on its tables.

To remove that delay, for x86_64 initially, grab a copy of
arch/x86/entry/syscalls/syscall_64.tbl and use it to generate those
tables.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-5n4sx1wp0ig75dwcghf9m6zs@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>