pwm: sifive: Simplify using devm_clk_get_prepared()

Instead of preparing the clk after it was requested and unpreparing in
.probe()'s error path and .remove(), use devm_clk_get_prepared() which
copes for unpreparing automatically.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-sifive.c

@@ -244,12 +244,12 @@ static int pwm_sifive_probe(struct platform_device *pdev)
 	if (IS_ERR(ddata->regs))
 		return PTR_ERR(ddata->regs);
 
-	ddata->clk = devm_clk_get(dev, NULL);
+	ddata->clk = devm_clk_get_prepared(dev, NULL);
 	if (IS_ERR(ddata->clk))
 		return dev_err_probe(dev, PTR_ERR(ddata->clk),
 				     "Unable to find controller clock\n");
 
-	ret = clk_prepare_enable(ddata->clk);
+	ret = clk_enable(ddata->clk);
 	if (ret) {
 		dev_err(dev, "failed to enable clock for pwm: %d\n", ret);
 		return ret;
@@ -308,7 +308,6 @@ static int pwm_sifive_probe(struct platform_device *pdev)
 		clk_disable(ddata->clk);
 		--enabled_clks;
 	}
-	clk_unprepare(ddata->clk);
 
 	return ret;
 }
@@ -327,8 +326,6 @@ static void pwm_sifive_remove(struct platform_device *dev)
 		if (pwm->state.enabled)
 			clk_disable(ddata->clk);
 	}
-
-	clk_unprepare(ddata->clk);
 }
 
 static const struct of_device_id pwm_sifive_of_match[] = {