Migrate headers to support platform specializations
Migrate headers to support platform specializations

  Add plat_target.H, fapi2_target.H
  Add plat_error_scope.H, fapi2_error_scope.H
  Update documentation to reflect platform support
  Wrap buffer print() API to remove from platforms
  Move target operators to platform specific files
  Move target states to target_states.H
  Add plat_hw_access, fapi2_hw_access.H
  Make op mode and pib error platform specific

Change-Id: I89252765c3f90ea4ac11c189001b25087aab956d
Original-Change-Id: If376f656b2b8a8f207332d42494dd3ce099790c6
Reviewed-on: http://gfw160.aus.stglabs.ibm.com:8080/gerrit/16970
Reviewed-by: Matt K. Light <19ba8ed73a0b3c376c81fced381f1ac0f483b7c2@us.ibm.com>
Reviewed-by: Thi N. Tran <25a2bca7ae5a8ea03be09ca8d282480c08c13052@us.ibm.com>
Reviewed-by: Brian Silver <af0eed78d989d9597decc8b92fa6db01ef8b58e0@us.ibm.com>
Tested-by: Brian Silver <af0eed78d989d9597decc8b92fa6db01ef8b58e0@us.ibm.com>

open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot