device-pine64-pinebookpro: add elogind subpackage
Move the elogind configuration and post-install call of "loginctl reload" into an extra subpackage with install_if=elogind.
Fix for:
Executing device-pine64-pinebookpro-16-r0.post-install
* service nvme-powersave added to runlevel boot
* service sysfsconf added to runlevel default
lib/apk/exec/device-pine64-pinebookpro-16-r0.post-install: line 5: loginctl: not found
ERROR: device-pine64-pinebookpro-16-r0.post-install: script exited with error 127
Make the post-install scripts more robust while at it, by adding "exit 0" at the end.