Linux: Move lio_listio, lio_listio64 from librt to libc

The symbols were moved using scripts/move-symbol-to-libc.py.
Placeholder symbols are needed on some architectures, to keep the
GLIBC_2.1 and GLIBC_2.4 symbol versions around.

Reviewed-by: Adhemerva Zanella <adhemerval.zanella@linaro.org>