Integrate meta-seconorth-distro/fix_rtc_postinst

Commit: seco-ne/yocto/layers/meta-seconorth-distro@4cf7267a

fng-install:rtc: Added device check to RTC post-install

Added a check to the RTC post-install script, that detects if the device is a Tanaro. If it is not, the check exits the script.

Cherry-picked from 247db5f3 and 3b84b29d