ath: unshare struct ath_bus_ops between ath5k and ath9k

This struct is not used in any common code, and moving it out of
the ath header makes it easier to add more driver specific ops.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath.h b/drivers/net/wireless/ath/ath.h
index 6d7105b..7cf4317 100644
--- a/drivers/net/wireless/ath/ath.h
+++ b/drivers/net/wireless/ath/ath.h
@@ -123,14 +123,7 @@
 };
 
 struct ath_common;
-
-struct ath_bus_ops {
-	enum ath_bus_type ath_bus_type;
-	void (*read_cachesize)(struct ath_common *common, int *csz);
-	bool (*eeprom_read)(struct ath_common *common, u32 off, u16 *data);
-	void (*bt_coex_prep)(struct ath_common *common);
-	void (*extn_synch_en)(struct ath_common *common);
-};
+struct ath_bus_ops;
 
 struct ath_common {
 	void *ah;