block: DAC960: Replace PCI pool old API

The PCI pool API is deprecated.  Replace the PCI pool old API by the
appropriate function with the DMA pool API.

Tested-by: Peter Senna Tschudin <peter.senna@collabora.com>
Signed-off-by: Romain Perier <romain.perier@collabora.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Peter Senna Tschudin <peter.senna@collabora.com>