ath9k_hw: add a new register op for read-mask-write

Reduces the number of calls to register ops. On MIPS this reduces the
ath9k_hw binary size from 321k down to 310k

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath.h

@@ -119,6 +119,7 @@ struct ath_ops {
 	void (*write)(void *, u32 val, u32 reg_offset);
 	void (*enable_write_buffer)(void *);
 	void (*write_flush) (void *);
+	u32 (*rmw)(void *, u32 reg_offset, u32 set, u32 clr);
 };
 
 struct ath_common;