clk: mediatek: Remove unused code from MT8173.

Remove unused header files from MT8173, and remove unused
keywords from function declaration.

Signed-off-by: James Liao <[e-mail]>
Reviewed-by: Daniel Kurtz <[e-mail]>

drivers/clk/mediatek/clk-mt8173.c

···
 #include <linux/clk.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
-#include <linux/slab.h>
-#include <linux/mfd/syscon.h>
 
 #include "clk-mtk.h"
 #include "clk-gate.h"

drivers/clk/mediatek/clk-mtk.h

···
 		.div = _div,				\
 	}
 
-extern void mtk_clk_register_factors(const struct mtk_fixed_factor *clks,
+void mtk_clk_register_factors(const struct mtk_fixed_factor *clks,
 		int num, struct clk_onecell_data *clk_data);
 
 struct mtk_composite {
···
 	const struct mtk_pll_div_table *div_table;
 };
 
-void __init mtk_clk_register_plls(struct device_node *node,
+void mtk_clk_register_plls(struct device_node *node,
 		const struct mtk_pll_data *plls, int num_plls,
 		struct clk_onecell_data *clk_data);