pinctrl: add the DM_UC_FLAG_SEQ_ALIAS flag for numbering the devices

It is possible to have multiple pin controllers in the system. Use the
DM_UC_FLAG_SEQ_ALIAS flag so that the pinctrl instances are assigned
a sequence number.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

drivers/pinctrl/pinctrl-uclass.c

@@ -287,5 +287,6 @@ static int pinctrl_post_bind(struct udevice *dev)
 UCLASS_DRIVER(pinctrl) = {
 	.id = UCLASS_PINCTRL,
 	.post_bind = pinctrl_post_bind,
+	.flags = DM_UC_FLAG_SEQ_ALIAS,
 	.name = "pinctrl",
 };