powerpc/powernv: Don't map M64 segments using M32DT

If M64 has been supported, the prefetchable 64-bits memory resources
shouldn't be mapped to the corresponding PE# via M32DT. Unfortunately,
we're doing that in pnv_ioda_setup_pe_seg() wrongly. The issue was
introduced by commit 262af557 ("powerpc/powernv: Enable M64 aperatus
for PHB3"). The patch fixes the issue by simply skipping M64 resources
when updating to M32DT.

Cc: <stable@vger.kernel.org>  # v3.17+
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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

@@ -1777,7 +1777,8 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
 				region.start += phb->ioda.io_segsize;
 				index++;
 			}
-		} else if (res->flags & IORESOURCE_MEM) {
+		} else if ((res->flags & IORESOURCE_MEM) &&
+			   !pnv_pci_is_mem_pref_64(res->flags)) {
 			region.start = res->start -
 				       hose->mem_offset[0] -
 				       phb->ioda.m32_pci_base;