AGESA fam12 fam14 fam15: Common handler for AGESA_DO_RESET

This is x86 "standard" 0xcf9 reset mechanism.

Change-Id: Ieb48290b21a7cb1425881fdd65c794e96da0248f
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5680
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
22 files changed