pinctrl: mediatek: mt8135/mt8173: Constify of_device_id table

Also make the table a bit compact.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Hongzhou Yang <hongzhou.yang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/mediatek/pinctrl-mt8173.c b/drivers/pinctrl/mediatek/pinctrl-mt8173.c
index f07cafb..46e4f6e 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mt8173.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mt8173.c
@@ -427,11 +427,9 @@
 	return mtk_pctrl_init(pdev, &mt8173_pinctrl_data);
 }
 
-static struct of_device_id mt8173_pctrl_match[] = {
-	{
-		.compatible = "mediatek,mt8173-pinctrl",
-	}, {
-	}
+static const struct of_device_id mt8173_pctrl_match[] = {
+	{ .compatible = "mediatek,mt8173-pinctrl", },
+	{ }
 };
 MODULE_DEVICE_TABLE(of, mt8173_pctrl_match);