clk: mediatek: add driver for MT8518

Add clock driver for MediaTek MT8518 SoC.

diff --git a/drivers/clk/mediatek/Makefile b/drivers/clk/mediatek/Makefile
index a47a5bd..e92bcd4 100644
--- a/drivers/clk/mediatek/Makefile
+++ b/drivers/clk/mediatek/Makefile
@@ -6,3 +6,4 @@
 obj-$(CONFIG_TARGET_MT7623) += clk-mt7623.o
 obj-$(CONFIG_TARGET_MT7629) += clk-mt7629.o
 obj-$(CONFIG_TARGET_MT8516) += clk-mt8516.o
+obj-$(CONFIG_TARGET_MT8518) += clk-mt8518.o