libqos/ahci: ATAPI support

libqos/ahci: ATAPI support

Add pathways to tolerate ATAPI commands.

Notably, unlike ATA, each SCSI command's layout is a little different,
so support will have to be patched in for each command as we want to
test them in e.g. ahci_command_set_sizes and ahci_command_set_offset.

For now, I'm adding support for 0x28, READ (10).

[Maintainer edit: replaced type-punning with stl_be_p(). --js]

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1452282920-21550-3-git-send-email-jsnow@redhat.com