ath9k: add support for overriding the MAC address through platform data

On some devices the correct MAC address is not in the EEPROM data, but
stored somewhere else.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/ath9k_platform.h b/include/linux/ath9k_platform.h
index b847fc7..b5f0658 100644
--- a/include/linux/ath9k_platform.h
+++ b/include/linux/ath9k_platform.h
@@ -23,6 +23,7 @@
 
 struct ath9k_platform_data {
 	u16 eeprom_data[ATH9K_PLAT_EEP_MAX_WORDS];
+	u8 *macaddr;
 };
 
 #endif /* _LINUX_ATH9K_PLATFORM_H */