dm: Drop the unused arg in uclass_find_device_by_seq()

Now that there is only one sequence number (rather than both requested and
assigned ones) we can simplify this function. Also update its caller to
simplify the logic.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-k3/j721e_init.c b/arch/arm/mach-k3/j721e_init.c
index a36e4ed..0201690 100644
--- a/arch/arm/mach-k3/j721e_init.c
+++ b/arch/arm/mach-k3/j721e_init.c
@@ -167,7 +167,7 @@
 	 * firmware (SYSFW) image for various purposes and SYSFW depends on us
 	 * to initialize its pin settings.
 	 */
-	ret = uclass_find_device_by_seq(UCLASS_SERIAL, 0, true, &dev);
+	ret = uclass_find_device_by_seq(UCLASS_SERIAL, 0, &dev);
 	if (!ret)
 		pinctrl_select_state(dev, "default");