s390/configs: Remove CONFIG_LSM

s390/configs: Remove CONFIG_LSM

s390 defconfig does not have BPF LSM, resulting in

    systemd[1]: bpf-restrict-fs: BPF LSM hook not enabled in the kernel, BPF LSM not supported.

with the respective kernels. The other architectures do not explicitly
set it, and the default values have BPF in them, so just drop it.

Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>