clk: cache parent clocks only for muxes

caching parent clocks makes sense only when a clock has more
than one parent (mux clocks).
Avoid doing this for every other clock.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
[mturquette@linaro.org: removed extra parentheses]
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/clk/clk.c

@@ -1235,8 +1235,8 @@ int __clk_init(struct device *dev, struct clk *clk)
 	 * If clk->parents is not NULL we skip this entire block.  This allows
 	 * for clock drivers to statically initialize clk->parents.
 	 */
-	if (clk->num_parents && !clk->parents) {
-		clk->parents = kmalloc((sizeof(struct clk*) * clk->num_parents),
+	if (clk->num_parents > 1 && !clk->parents) {
+		clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents),
 				GFP_KERNEL);
 		/*
 		 * __clk_lookup returns NULL for parents that have not been