Merge changes from topic "fw_config_handoff" into integration

* changes:
  doc: Update memory layout for firmware configuration area
  plat/arm: Increase size of firmware configuration area
  plat/arm: Load and populate fw_config and tb_fw_config
  fconf: Handle error from fconf_load_config
  plat/arm: Update the fw_config load call and populate it's information
  fconf: Allow fconf to load additional firmware configuration
  fconf: Clean confused naming between TB_FW and FW_CONFIG
  tbbr/dualroot: Add fw_config image in chain of trust
  cert_tool: Update cert_tool for fw_config image support
  fiptool: Add fw_config in FIP
  plat/arm: Rentroduce tb_fw_config device tree