/usr/mipsel-linux-gnu/lib64/libnss_files.so.2 is in libc6-mips64-mipsel-cross 2.27-3ubuntu1cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/mipsel-linux-gnu/lib64/libnss_files-2.27.so
/usr/mipsel-linux-gnu/lib64/libnss_files-2.27.so