ahci: disable MSI instead of NCQ on Samsung pci-e SSDs on macbooks

Samsung pci-e SSDs on macbooks failed miserably on NCQ commands, so
67809f85

 ("ahci: disable NCQ on Samsung pci-e SSDs on macbooks")
disabled NCQ on them.  It turns out that NCQ is fine as long as MSI is
not used, so let's turn off MSI and leave NCQ on.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=60731


Tested-by:  <dorin@i51.org>
Tested-by: Imre Kaloz <kaloz@openwrt.org>
Cc: stable@vger.kernel.org
Fixes: 67809f85 ("ahci: disable NCQ on Samsung pci-e SSDs on macbooks")