cpts: fix a run time warn_on.

This patch fixes a warning in clk_enable by calling clk_prepare_enable
instead.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/cpts.c

@@ -247,7 +247,7 @@ static void cpts_clk_init(struct cpts *cpts)
 		cpts->refclk = NULL;
 		return;
 	}
-	clk_enable(cpts->refclk);
+	clk_prepare_enable(cpts->refclk);
 }
 
 static void cpts_clk_release(struct cpts *cpts)