powerpc/powernv: Update dev->dma_mask in pci_set_dma_mask() path

powerpc defines various machine-specific routines for handling
pci_set_dma_mask().  The routines for machine "PowerNV" may neglect
to set dev->dma_mask.  This could confuse anyone (e.g. drivers) that
consult dev->dma_mask to find the current mask.  Set the dma_mask in
the PowerNV leaf routine.
Signed-off-by: Brian W. Hart <hartb@linux.vnet.ibm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/powernv/pci-ioda.c

@@ -491,6 +491,7 @@ static int pnv_pci_ioda_dma_set_mask(struct pnv_phb *phb,
 		set_dma_ops(&pdev->dev, &dma_iommu_ops);
 		set_iommu_table_base(&pdev->dev, &pe->tce32_table);
 	}
+	*pdev->dev.dma_mask = dma_mask;
 	return 0;
 }