Different AHCI controllers have a different number of ports, so the core
shouldn't care about the amount of ports available.

This patch makes the number of ports available to the AHCI core runtime
configurable, allowing us to have multiple different AHCI implementations
with different amounts of ports.
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>