AGESA: Add common callouts

Most of the callouts are not specific to board or even family.
Start new file with default callouts doing nothing and returning
either AGESA_SUCCESS or AGESA_UNSUPPORTED.

Also add callout for returning empty IdsIdData. This feature is
not used and could be easily overriden at board-level at later time.

Change-Id: I65dbcdd80dddc89d47669ebe62c22caa63792f5c
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5678
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
43 files changed