clk: fix compile for OF && !COMMON_CLK

With commit 766e6a4ec602d0c107 (clk: add DT clock binding support),
compiling with OF && !COMMON_CLK is broken.

Reported-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Reported-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/clk/clkdev.c

@@ -24,7 +24,7 @@
 static LIST_HEAD(clocks);
 static DEFINE_MUTEX(clocks_mutex);
 
-#ifdef CONFIG_OF
+#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
 struct clk *of_clk_get(struct device_node *np, int index)
 {
 	struct of_phandle_args clkspec;

include/linux/clk.h

@@ -314,7 +314,7 @@ int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
 struct device_node;
 struct of_phandle_args;
 
-#ifdef CONFIG_OF
+#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
 struct clk *of_clk_get(struct device_node *np, int index);
 struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);