iwlagn: use iwl_eeprom_calib_hdr structure

For retrieve calibration hdr related information, instead of using structure in
one place and #define in other place, unify the method to use data structure.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-eeprom.h b/drivers/net/wireless/iwlwifi/iwl-eeprom.h
index 325753e..c94747e 100644
--- a/drivers/net/wireless/iwlwifi/iwl-eeprom.h
+++ b/drivers/net/wireless/iwlwifi/iwl-eeprom.h
@@ -163,11 +163,16 @@
 } __packed;
 
 /* calibration */
+struct iwl_eeprom_calib_hdr {
+	u8 version;
+	u8 pa_type;
+	__le16 voltage;
+} __packed;
+
 #define EEPROM_CALIB_ALL	(INDIRECT_ADDRESS | INDIRECT_CALIBRATION)
 #define EEPROM_XTAL		((2*0x128) | EEPROM_CALIB_ALL)
 
 /* temperature */
-#define EEPROM_VOLTAGE_READING		((2*0x1) | EEPROM_CALIB_ALL)
 #define EEPROM_KELVIN_TEMPERATURE	((2*0x12A) | EEPROM_CALIB_ALL)
 #define EEPROM_RAW_TEMPERATURE		((2*0x12B) | EEPROM_CALIB_ALL)