mt76: fix build error implicit enumeration conversion

drivers/net/wireless/mediatek/mt76/mt7915/mcu.c:114:10: error: implicit
conversion from enumeration type 'enum mt76_cipher_type' to different
enumeration type 'enum mcu_cipher_type' [-Werror,-Wenum-conversion]
                return MT_CIPHER_NONE;
                ~~~~~~ ^~~~~~~~~~~~~~

drivers/net/wireless/mediatek/mt76/mt7921/mcu.c:114:10: error: implicit
conversion from enumeration type 'enum mt76_cipher_type' to different
enumeration type 'enum mcu_cipher_type' [-Werror,-Wenum-conversion]
                return MT_CIPHER_NONE;
                ~~~~~~ ^~~~~~~~~~~~~~

Fixes: c368362c ("mt76: fix iv and CCMP header insertion")
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7915/mcu.c

@@ -1201,7 +1201,7 @@ mt7915_mcu_sta_key_tlv(struct mt7915_sta *msta, struct sk_buff *skb,
 		u8 cipher;
 
 		cipher = mt7915_mcu_get_cipher(key->cipher);
-		if (cipher == MT_CIPHER_NONE)
+		if (cipher == MCU_CIPHER_NONE)
 			return -EOPNOTSUPP;
 
 		sec_key = &sec->key[0];

drivers/net/wireless/mediatek/mt76/mt7921/mcu.c

@@ -618,7 +618,7 @@ mt7921_mcu_sta_key_tlv(struct mt7921_sta *msta, struct sk_buff *skb,
 		u8 cipher;
 
 		cipher = mt7921_mcu_get_cipher(key->cipher);
-		if (cipher == MT_CIPHER_NONE)
+		if (cipher == MCU_CIPHER_NONE)
 			return -EOPNOTSUPP;
 
 		sec_key = &sec->key[0];