fix compatibility with systemd 255 handle systemd-pcr{phase -> extend} rename

See https://github.com/dracutdevs/dracut/issues/2583

Describe the bug With the systemd version 255, the systemd-pcrphase binary was renamed to systemd-pcrextend, breaking dracut initrds requiring it.

Distribution used Arch linux

Dracut version dracut 059

Init system systemd