Integrate meta-seconorth-distro/update-sshd-config

Commit: seco-ne/yocto/layers/meta-seconorth-distro@41c2cbb2

ssh: make sshd config more secure

By analogy with sshd config in Jethro BSP:

• allow only connections which use a modern version (2) of SSH protocol;
• make sshd to use an unprivileged child process to handle incoming traffic and impose additional restrictions via sandbox.

Signed-off-by: Mikhail Vanyulin mikhail.vanyulin@rtsoft.de