libata: replace ap->cbl tests with ATA_FLAG_SATA tests

ap->cbl == ATA_CBL_SATA indicates SATA cable while ap->flags &
ATA_FLAG_SATA indicates SATA host port.  Till now they always gave the
same result but SATA/PATA bridge handling will change that.  Switch to
ATA_FLAG_SATA test if we're testing for host port type.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>