pwm: brcmstb: Checked clk_prepare_enable() return value

Check the clk_prepare_enable() return value and propagate it.

Suggested-by: Uwe Kleine-König <[e-mail]>
Signed-off-by: Florian Fainelli <[e-mail]>
Reviewed-by: Uwe Kleine-König <[e-mail]>
Signed-off-by: Thierry Reding <[e-mail]>

drivers/pwm/pwm-brcmstb.c

···
 {
 	struct brcmstb_pwm *p = dev_get_drvdata(dev);
 
-	clk_prepare_enable(p->clk);
-
-	return 0;
+	return clk_prepare_enable(p->clk);
 }
 #endif