pinctrl: madera: Return ENOTSUPP for unsupported pin attributes

The pin_config_[get|set] functions should return ENOTSUPP if
the requested attribute isn't supported.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/cirrus/pinctrl-madera-core.c

@@ -801,7 +801,7 @@ static int madera_pin_conf_get(struct pinctrl_dev *pctldev, unsigned int pin,
 			result = 1;
 		break;
 	default:
-		break;
+		return -ENOTSUPP;
 	}
 
 	*config = pinconf_to_config_packed(param, result);
@@ -905,7 +905,7 @@ static int madera_pin_conf_set(struct pinctrl_dev *pctldev, unsigned int pin,
 			conf[1] &= ~MADERA_GP1_DIR;
 			break;
 		default:
-			break;
+			return -ENOTSUPP;
 		}
 
 		++configs;