Merge changes from topic 'avb-early-mount' into oc-dev

* changes:
  fs_mgr: support AVB in fs_mgr_update_verity_state()
  init: support early_mount with vboot 2.0 (external/avb/libavb)
  fs_mgr: adds/changes some public APIs for early mount in init
  fs_mgr_avb: refactors how vbmeta is loaded
  fs_mgr: adding fs_mgr_get_slot_suffix() public API