wil6210: add per-MCS Rx stats

Provide detailed statistics for the Rx frames per MCS
Statistics printed in "stations" debugfs entry

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
diff --git a/drivers/net/wireless/ath/wil6210/wil6210.h b/drivers/net/wireless/ath/wil6210/wil6210.h
index ea0163c..c39369f 100644
--- a/drivers/net/wireless/ath/wil6210/wil6210.h
+++ b/drivers/net/wireless/ath/wil6210/wil6210.h
@@ -464,6 +464,7 @@
 };
 
 #define WIL_STA_TID_NUM (16)
+#define WIL_MCS_MAX (12) /* Maximum MCS supported */
 
 struct wil_net_stats {
 	unsigned long	rx_packets;
@@ -473,6 +474,7 @@
 	unsigned long	tx_errors;
 	unsigned long	rx_dropped;
 	u16 last_mcs_rx;
+	u64 rx_per_mcs[WIL_MCS_MAX + 1];
 };
 
 /**