wil6210: count drops in Rx block ack reorder

When performing Rx reordering, count skb's dropped
per reorder buffer; and print dropped packets count
on the "stations" debugfs entry

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/wil6210/wil6210.h

@@ -426,6 +426,7 @@ struct pci_dev;
  * @timeout: reset timer value (in TUs).
  * @dialog_token: dialog token for aggregation session
  * @rcu_head: RCU head used for freeing this struct
+ * @drop: total frames dropped for this reorder buffer
  *
  * This structure's lifetime is managed by RCU, assignments to
  * the array holding it must hold the aggregation mutex.
@@ -443,6 +444,7 @@ struct wil_tid_ampdu_rx {
 	u16 buf_size;
 	u16 timeout;
 	u16 ssn_last_drop;
+	unsigned long long drop;
 	u8 dialog_token;
 	bool first_time; /* is it 1-st time this buffer used? */
 };