fdt: Tighten up error handling in fdtdec_get_pci_addr()

This function returns -ENOENT when the property is missing (which the caller
might forgive) and also when the property is present but incorrectly
formatted (which many callers would like to report).

Update the error return value to allow these different situations to be
distinguished.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

include/fdtdec.h

@@ -327,7 +327,9 @@ fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
  * @param type		pci address type (FDT_PCI_SPACE_xxx)
  * @param prop_name	name of property to find
  * @param addr		returns pci address in the form of fdt_pci_addr
- * @return 0 if ok, negative on error
+ * @return 0 if ok, -ENOENT if the property did not exist, -EINVAL if the
+ *		format of the property was invalid, -ENXIO if the requested
+ *		address type was not found
  */
 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
 		const char *prop_name, struct fdt_pci_addr *addr);

lib/fdtdec.c

@@ -160,8 +160,10 @@ int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
 			}
 		}
 
-		if (i == num)
+		if (i == num) {
+			ret = -ENXIO;
 			goto fail;
+		}
 
 		return 0;
 	} else {