Revert "units/initrd-*: require initrd-fs.target rather than local-fs.target"

This reverts commit 7d89ce303fb59743a4392eeb3110c00f100172ca.
Revert "add initrd-fs.target and initrd-fs-pre.target"

This reverts commit 39b83cdab37623a546344622db9bbbc784c15df5.
initrd-parse-etc.servic: force start local-fs.target