AHCI spec explicitly states that we may poll.
TEST=Ran FILO on kontron/bsl6 and observed that the controller
always becomes ready during the first delay.
Change-Id: If34694abff14d719d10d89bc6771dbfa12065071
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/20764
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>