sony-nicki: Fix elogind/cgroups regression, remove unused defconfig

Without this MR, elogind, and therefore weston will not start as it will complain about cgroup mess:

[   21.387150] elogind-daemon[1538]: Failed to determine whether /sys/fs/cgroup is a mount point: Symbolic link loop
[   21.388341] elogind-daemon[1538]: Failed to mount cgroup at /sys/fs/cgroup/elogind: No such file or directory

Fixed by applying this patch, thanks @minlexx for pointing me to it! This might possibly also be applicable to other kernel 3.4-based ports.