PCI: dwc: Use resource start as ioremap() input in dw_pcie_pme_turn_off()

The msg_res region translates writes into PCIe Message TLPs. Previously we
mapped this region using atu.cpu_addr, the input address programmed into
the ATU.

"cpu_addr" is a misnomer because when a bus fabric translates addresses
between the CPU and the ATU, the ATU input address is different from the
CPU address.  A future patch will rename "cpu_addr" and correct the value
to be the ATU input address instead of the CPU physical address.

Map the msg_res region before writing to it using the msg_res resource
start, a CPU physical address.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Frank Li <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>

Author: nxpfrankli

drivers/pci/controller/dwc/pcie-designware-host.c

@@ -908,7 +908,7 @@ static int dw_pcie_pme_turn_off(struct dw_pcie *pci)
 	if (ret)
 		return ret;
 
-	mem = ioremap(atu.cpu_addr, pci->region_align);
+	mem = ioremap(pci->pp.msg_res->start, pci->region_align);
 	if (!mem)
 		return -ENOMEM;