clk: mediatek: provide common clk init function for infrasys

Provide common clk init function for infrasys that defaults to topckgen
driver if clock-parent is not defined. This is the case for upstream
DTSI that doesn't provide this entry.

This is needed for infracfg driver that will make use of the unified
gates + muxes implementation.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
diff --git a/drivers/clk/mediatek/clk-mtk.c b/drivers/clk/mediatek/clk-mtk.c
index 011615a..35ea982 100644
--- a/drivers/clk/mediatek/clk-mtk.c
+++ b/drivers/clk/mediatek/clk-mtk.c
@@ -708,8 +708,9 @@
 	.get_rate = mtk_clk_gate_get_rate,
 };
 
-int mtk_common_clk_init(struct udevice *dev,
-			const struct mtk_clk_tree *tree)
+static int mtk_common_clk_init_drv(struct udevice *dev,
+				   const struct mtk_clk_tree *tree,
+				   const struct driver *drv)
 {
 	struct mtk_clk_priv *priv = dev_get_priv(dev);
 	struct udevice *parent;
@@ -721,8 +722,7 @@
 
 	ret = uclass_get_device_by_phandle(UCLASS_CLK, dev, "clock-parent", &parent);
 	if (ret || !parent) {
-		ret = uclass_get_device_by_driver(UCLASS_CLK,
-				DM_DRIVER_GET(mtk_clk_apmixedsys), &parent);
+		ret = uclass_get_device_by_driver(UCLASS_CLK, drv, &parent);
 		if (ret || !parent)
 			return -ENOENT;
 	}
@@ -733,6 +733,20 @@
 	return 0;
 }
 
+int mtk_common_clk_init(struct udevice *dev,
+			const struct mtk_clk_tree *tree)
+{
+	return mtk_common_clk_init_drv(dev, tree,
+				       DM_DRIVER_GET(mtk_clk_apmixedsys));
+}
+
+int mtk_common_clk_infrasys_init(struct udevice *dev,
+				 const struct mtk_clk_tree *tree)
+{
+	return mtk_common_clk_init_drv(dev, tree,
+				       DM_DRIVER_GET(mtk_clk_topckgen));
+}
+
 int mtk_common_clk_gate_init(struct udevice *dev,
 			     const struct mtk_clk_tree *tree,
 			     const struct mtk_gate *gates)
diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h
index 4423689..e9c8a52 100644
--- a/drivers/clk/mediatek/clk-mtk.h
+++ b/drivers/clk/mediatek/clk-mtk.h
@@ -266,6 +266,8 @@
 
 int mtk_common_clk_init(struct udevice *dev,
 			const struct mtk_clk_tree *tree);
+int mtk_common_clk_infrasys_init(struct udevice *dev,
+				 const struct mtk_clk_tree *tree);
 int mtk_common_clk_gate_init(struct udevice *dev,
 			     const struct mtk_clk_tree *tree,
 			     const struct mtk_gate *gates);