drivers/of: Add empty ranges quirk for PA-Semi

The "sdc" node is missing the ranges property, it needs to be treated
as having an empty one otherwise translation fails for its children.

Fixes 746c9e9, "of/base: Fix PowerPC address parsing hack"

Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Cc: Stable <stable@vger.kernel.org> # v3.18+

drivers/of/address.c

@@ -450,12 +450,17 @@ static struct of_bus *of_match_bus(struct device_node *np)
 	return NULL;
 }
 
-static int of_empty_ranges_quirk(void)
+static int of_empty_ranges_quirk(struct device_node *np)
 {
 	if (IS_ENABLED(CONFIG_PPC)) {
-		/* To save cycles, we cache the result */
+		/* To save cycles, we cache the result for global "Mac" setting */
 		static int quirk_state = -1;
 
+		/* PA-SEMI sdc DT bug */
+		if (of_device_is_compatible(np, "1682m-sdc"))
+			return true;
+
+		/* Make quirk cached */
 		if (quirk_state < 0)
 			quirk_state =
 				of_machine_is_compatible("Power Macintosh") ||
@@ -490,7 +495,7 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
 	 * This code is only enabled on powerpc. --gcl
 	 */
 	ranges = of_get_property(parent, rprop, &rlen);
-	if (ranges == NULL && !of_empty_ranges_quirk()) {
+	if (ranges == NULL && !of_empty_ranges_quirk(parent)) {
 		pr_debug("OF: no ranges; cannot translate\n");
 		return 1;
 	}