AGESA boards: Drop global bus_isa

Only ever used as lvalue (except when incrementing) so this global
is unused.

Change-Id: I616721f937eb0bfdb28f356284efd70f99ccd2dd
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/6330
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
40 files changed