of: make PowerMac cache node search conditional on CONFIG_PPC_PMAC

[ Upstream commit f6707fd6241e483f6fea2caae82d876e422bb11a ]

Cache nodes under the cpu node(s) is PowerMac specific according to the
comment above, so make the code enforce that.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/of/base.c b/drivers/of/base.c
index f366af1..c66cdc4 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2281,7 +2281,7 @@
 	/* OF on pmac has nodes instead of properties named "l2-cache"
 	 * beneath CPU nodes.
 	 */
-	if (!strcmp(np->type, "cpu"))
+	if (IS_ENABLED(CONFIG_PPC_PMAC) && !strcmp(np->type, "cpu"))
 		for_each_child_of_node(np, child)
 			if (!strcmp(child->type, "cache"))
 				return child;