dm: core: Drop unused parameter from dm_scan_fdt()

This doesn't need to be passed the devicetree anymore. Drop it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/dm/test-fdt.c b/test/dm/test-fdt.c
index cc12419..9507636 100644
--- a/test/dm/test-fdt.c
+++ b/test/dm/test-fdt.c
@@ -308,7 +308,7 @@
 	struct uclass *uc;
 	int ret;
 
-	ret = dm_scan_fdt(gd->fdt_blob, true);
+	ret = dm_scan_fdt(true);
 	ut_assert(!ret);
 
 	ret = uclass_get(UCLASS_TEST_FDT, &uc);