clk: mediatek: Refine the makefile to support multiple clock drivers

Add a Kconfig to define clock configuration for each SoC, and
modify the Makefile to build drivers that only selected in config.
Signed-off-by: Shunli Wang <shunli.wang@mediatek.com>
Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
Signed-off-by: Erin Lo <erin.lo@mediatek.com>
Tested-by: John Crispin <blogic@openwrt.org>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/Kconfig

@@ -200,6 +200,7 @@ config COMMON_CLK_OXNAS
 
 source "drivers/clk/bcm/Kconfig"
 source "drivers/clk/hisilicon/Kconfig"
+source "drivers/clk/mediatek/Kconfig"
 source "drivers/clk/meson/Kconfig"
 source "drivers/clk/mvebu/Kconfig"
 source "drivers/clk/qcom/Kconfig"

drivers/clk/mediatek/Kconfig

+#
+# MediaTek SoC drivers
+#
+config COMMON_CLK_MEDIATEK
+	bool
+	---help---
+	  Mediatek SoCs' clock support.
+
+config COMMON_CLK_MT8135
+	bool "Clock driver for Mediatek MT8135"
+	select COMMON_CLK_MEDIATEK
+	default ARCH_MEDIATEK
+	---help---
+	  This driver supports Mediatek MT8135 clocks.
+
+config COMMON_CLK_MT8173
+	bool "Clock driver for Mediatek MT8173"
+	select COMMON_CLK_MEDIATEK
+	default ARCH_MEDIATEK
+	---help---
+	  This driver supports Mediatek MT8173 clocks.

drivers/clk/mediatek/Makefile

-obj-y += clk-mtk.o clk-pll.o clk-gate.o clk-apmixed.o
+obj-$(CONFIG_COMMON_CLK_MEDIATEK) += clk-mtk.o clk-pll.o clk-gate.o clk-apmixed.o
 obj-$(CONFIG_RESET_CONTROLLER) += reset.o
-obj-y += clk-mt8135.o
-obj-y += clk-mt8173.o
+obj-$(CONFIG_COMMON_CLK_MT8135) += clk-mt8135.o
+obj-$(CONFIG_COMMON_CLK_MT8173) += clk-mt8173.o