ARM: plat-versatile: remove stale clock header

All the Versatile platforms (Integrator, Versatile, RealView
Versatile Express) have been migrated to use the drivers/clk
subsystem. Clean out this header that is not referenced
anywhere anymore.
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/plat-versatile/include/plat/clock.h

-#ifndef PLAT_CLOCK_H
-#define PLAT_CLOCK_H
-
-#include <asm/hardware/icst.h>
-
-struct clk_ops {
-	long	(*round)(struct clk *, unsigned long);
-	int	(*set)(struct clk *, unsigned long);
-	void	(*setvco)(struct clk *, struct icst_vco);
-};
-
-int icst_clk_set(struct clk *, unsigned long);
-long icst_clk_round(struct clk *, unsigned long);
-
-#endif