clk: add "const" for clk_ops of basic clks

The clk_ops of basic clks should have "const" to match the definition
in "struct clk" and clk_register prototype.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
index 45cad61..5424488 100644
--- a/drivers/clk/clk-mux.c
+++ b/drivers/clk/clk-mux.c
@@ -82,7 +82,7 @@
 	return 0;
 }
 
-struct clk_ops clk_mux_ops = {
+const struct clk_ops clk_mux_ops = {
 	.get_parent = clk_mux_get_parent,
 	.set_parent = clk_mux_set_parent,
 };