pinctrl: airoha: Fix return value in pinconf callbacks

Pinctrl stack requires ENOTSUPP error code if the parameter is not
supported by the pinctrl driver. Fix the returned error code in pinconf
callbacks if the operation is not supported.

Fixes: 1c8ace2 ("pinctrl: airoha: Add support for EN7581 SoC")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/20250822-airoha-pinconf-err-val-fix-v1-1-87b4f264ced2@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: LorenzoBianconi

drivers/pinctrl/mediatek/pinctrl-airoha.c

@@ -2696,7 +2696,7 @@ static int airoha_pinconf_get(struct pinctrl_dev *pctrl_dev,
 		arg = 1;
 		break;
 	default:
-		return -EOPNOTSUPP;
+		return -ENOTSUPP;
 	}
 
 	*config = pinconf_to_config_packed(param, arg);
@@ -2788,7 +2788,7 @@ static int airoha_pinconf_set(struct pinctrl_dev *pctrl_dev,
 			break;
 		}
 		default:
-			return -EOPNOTSUPP;
+			return -ENOTSUPP;
 		}
 	}
 
@@ -2805,10 +2805,10 @@ static int airoha_pinconf_group_get(struct pinctrl_dev *pctrl_dev,
 		if (airoha_pinconf_get(pctrl_dev,
 				       airoha_pinctrl_groups[group].pins[i],
 				       config))
-			return -EOPNOTSUPP;
+			return -ENOTSUPP;
 
 		if (i && cur_config != *config)
-			return -EOPNOTSUPP;
+			return -ENOTSUPP;
 
 		cur_config = *config;
 	}