of: Handle memory@0 node on PPC32 only

In order to deal with an firmware bug on a specific ppc32 platform
(longtrail), early_init_dt_scan_memory() looks for a node called
memory@0 on all platforms. Restrict this quirk to ppc32 kernels only.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

drivers/of/fdt.c

@@ -748,7 +748,7 @@ int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 		 * The longtrail doesn't have a device_type on the
 		 * /memory node, so look for the node called /memory@0.
 		 */
-		if (depth != 1 || strcmp(uname, "memory@0") != 0)
+		if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
 			return 0;
 	} else if (strcmp(type, "memory") != 0)
 		return 0;