ath9k_htc: Remove unused structures

	u8 credits;

} __packed;

struct htc_packet {

	void *pktcontext;

	u8 *buf;

	u8 *buf_payload;

	u32 buflen;

	u32 payload_len;

	int endpoint;

	int status;

	void *context;

	u32 reserved;

};

struct htc_ep_callbacks {

	void *priv;

	void (*tx) (void *, struct sk_buff *, enum htc_endpoint_id, bool txok);

#define HTC_CONTROL_BUFFER_SIZE	\

	(HTC_MAX_CONTROL_MESSAGE_LENGTH + sizeof(struct htc_frame_hdr))

struct htc_control_buf {

	struct htc_packet htc_pkt;

	u8 buf[HTC_CONTROL_BUFFER_SIZE];

};

#define HTC_OP_START_WAIT           BIT(0)

#define HTC_OP_CONFIG_PIPE_CREDITS  BIT(1)