ARM: ux500: Add placeholder for clk_set_parent

Calling clk_set_parent (e.g. from Ux500 ASoC-driver) generates
build-errors.
Signed-off-by: Ola Lilja <ola.o.lilja@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/mach-ux500/clock.c

@@ -223,6 +223,13 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
 }
 EXPORT_SYMBOL(clk_set_rate);
 
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	/*TODO*/
+	return -ENOSYS;
+}
+EXPORT_SYMBOL(clk_set_parent);
+
 static void clk_prcmu_enable(struct clk *clk)
 {
 	void __iomem *cg_set_reg = __io_address(U8500_PRCMU_BASE)

arch/arm/mach-ux500/clock.h

@@ -21,6 +21,7 @@ struct clkops {
 	void (*enable) (struct clk *);
 	void (*disable) (struct clk *);
 	unsigned long (*get_rate) (struct clk *);
+	int (*set_parent)(struct clk *, struct clk *);
 };
 
 /**