ath9k_hw: fix sparse complaint on ar9003_switch_com_spdt_get()

This fixes this sparse complaint:

make C=2 CF="-D__CHECK_ENDIAN__" M=drivers/net/wireless/ath/

  CHECK   drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
drivers/net/wireless/ath/ath9k/ar9003_eeprom.c:3544:21: warning: incorrect type in assignment (different base types)
drivers/net/wireless/ath/ath9k/ar9003_eeprom.c:3544:21:    expected restricted __le32 [usertype] val
drivers/net/wireless/ath/ath9k/ar9003_eeprom.c:3544:21:    got restricted __le16 [usertype] switchcomspdt
drivers/net/wireless/ath/ath9k/ar9003_eeprom.c:3546:21: warning: incorrect type in assignment (different base types)
drivers/net/wireless/ath/ath9k/ar9003_eeprom.c:3546:21:    expected restricted __le32 [usertype] val
drivers/net/wireless/ath/ath9k/ar9003_eeprom.c:3546:21:    got restricted __le16 [usertype] switchcomspdt

The eep->modalHeader5G.switchcomspdt is a le16 and we return u16,
so just return le16_to_cpu().

Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ar9003_eeprom.c

@@ -3538,13 +3538,13 @@ static void ar9003_hw_xpa_bias_level_apply(struct ath_hw *ah, bool is2ghz)
 static u16 ar9003_switch_com_spdt_get(struct ath_hw *ah, bool is_2ghz)
 {
 	struct ar9300_eeprom *eep = &ah->eeprom.ar9300_eep;
-	__le32 val;
+	__le16 val;
 
 	if (is_2ghz)
 		val = eep->modalHeader2G.switchcomspdt;
 	else
 		val = eep->modalHeader5G.switchcomspdt;
-	return le32_to_cpu(val);
+	return le16_to_cpu(val);
 }