dm: core: Don't show an ACPI warning if there is no ordering

Some boards don't care about the ordering of ACPI code fragments. Change
the warning to a debug message.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/core/acpi.c b/drivers/core/acpi.c
index cdbc2c5..7fe9399 100644
--- a/drivers/core/acpi.c
+++ b/drivers/core/acpi.c
@@ -195,7 +195,7 @@
 					"u-boot,acpi-dsdt-order" :
 					"u-boot,acpi-ssdt-order", &size);
 	if (!order) {
-		log_warning("Failed to find ordering, leaving as is\n");
+		log_debug("Failed to find ordering, leaving as is\n");
 		return 0;
 	}