Integrate meta-seconorth-distro/fng-install-postinstall
-- Commit: seco-ne/yocto/layers/meta-seconorth-distro@83f74a24 fng-install: Clarify interface between fng-install and postinstall steps
-- Commit: seco-ne/yocto/layers/meta-seconorth-distro@83f74a24 fng-install: Clarify interface between fng-install and postinstall steps