clk: mediatek: Properly include clk.h

We don't need to include clk.h in header files, just forward
declare struct clk here. This leads us to a few places where the
include of clk.h was missing in C files. Add them.

Cc: James Liao <jamesjj.liao@mediatek.com>
Cc: Henry Chen <henryc.chen@mediatek.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/mediatek/clk-gate.h

@@ -16,9 +16,10 @@
 #define __DRV_CLK_GATE_H
 
 #include <linux/regmap.h>
-#include <linux/clk.h>
 #include <linux/clk-provider.h>
 
+struct clk;
+
 struct mtk_clk_gate {
 	struct clk_hw	hw;
 	struct regmap	*regmap;