mips64-linux: set ac_cv_sizeof_ssize_t for mips64el
The fix for [YOCTO #5935] was applied for mips64 but not for mips64el
Patch it for mips64el
For description of issue, check OE-Core 7a5b6b96
Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>