[ARM] versatile: convert to clkdev and lookup clocks by device name

People often point to the Integrator/Versatile/Realview
implementations to justify using the consumer name as the sole
selector for clocks.

Eliminate this excuse by changing the Versatile implementation, so
it provides a better example of how it should be done.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-versatile/clock.h

@@ -12,14 +12,9 @@ struct module;
 struct icst307_params;
 
 struct clk {
-	struct list_head	node;
 	unsigned long		rate;
-	struct module		*owner;
-	const char		*name;
 	const struct icst307_params *params;
+	u32			oscoff;
 	void			*data;
 	void			(*setvco)(struct clk *, struct icst307_vco vco);
 };
-
-int clk_register(struct clk *clk);
-void clk_unregister(struct clk *clk);