ath6kl: document all spinlocks

Also fixes quite a few checkpatch warnings like this:

ath6kl/hif.h:226: CHECK: spinlock_t definition without comment

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
diff --git a/drivers/net/wireless/ath/ath6kl/htc.h b/drivers/net/wireless/ath/ath6kl/htc.h
index 2de4d6f..5027ccc 100644
--- a/drivers/net/wireless/ath/ath6kl/htc.h
+++ b/drivers/net/wireless/ath/ath6kl/htc.h
@@ -523,9 +523,16 @@
 	struct ath6kl_htc_credit_info *credit_info;
 	int tgt_creds;
 	unsigned int tgt_cred_sz;
+
+	/* protects free_ctrl_txbuf and free_ctrl_rxbuf */
 	spinlock_t htc_lock;
+
+	/* FIXME: does this protext rx_bufq and endpoint structures or what? */
 	spinlock_t rx_lock;
+
+	/* protects endpoint->txq */
 	spinlock_t tx_lock;
+
 	struct ath6kl_device *dev;
 	u32 htc_flags;
 	u32 rx_st_flags;