PCI: cadence: Do not error if "cdns,max-outbound-regions" is not found

Now that "cdns,max-outbound-regions" is made an optional property, do
not error out if "cdns,max-outbound-regions" device tree property is
not found.

Link: http://lore.kernel.org/r/20201105165331.GA55814@bogus
Link: https://lore.kernel.org/r/20201106151107.3987-3-kishon@ti.comSigned-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: NRob Herring <robh@kernel.org>

drivers/pci/controller/cadence/pcie-cadence-ep.c

@@ -530,12 +530,9 @@ int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
 	}
 	pcie->mem_res = res;
 
-	ret = of_property_read_u32(np, "cdns,max-outbound-regions",
-				   &ep->max_regions);
-	if (ret < 0) {
-		dev_err(dev, "missing \"cdns,max-outbound-regions\"\n");
-		return ret;
-	}
+	ep->max_regions = CDNS_PCIE_MAX_OB;
+	of_property_read_u32(np, "cdns,max-outbound-regions", &ep->max_regions);
+
 	ep->ob_addr = devm_kcalloc(dev,
 				   ep->max_regions, sizeof(*ep->ob_addr),
 				   GFP_KERNEL);

drivers/pci/controller/cadence/pcie-cadence.h

@@ -197,6 +197,7 @@ enum cdns_pcie_rp_bar {
 };
 
 #define CDNS_PCIE_RP_MAX_IB	0x3
+#define CDNS_PCIE_MAX_OB	32
 
 struct cdns_pcie_rp_ib_bar {
 	u64 size;