Revert "imx: keep boot device info for partition reboot"

This reverts commit 8673a8e5abfea5de60680823467ac224526b530f.

SCFW already supported OCRAM retention, so no need to change
primary CPU's boot entry.

(cherry picked from commit e49e1c05893f1d6394361761ce462094796c9044)
4 files changed