ath9k_hw: fix sparse complaint on ar9003_switch_com_spdt_get()

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>