qcacmn: Drop packets from RXDMA2SW ring on the non-monitoring MAC

In monitor mode, if channel is initially configured from 5G
band and then moved to channel from 2G band, packets are still
received on MAC-0 RXDMA2SW ring since IMPS is disabled for both
MACs. Since driver reaps only MAC-1 RXDMA2SW ring, ring full
condition is hit for the MAC-0 ring causing ring backpressure.

Fix is to drop packets received on the non-monitoring MAC
ring.

Change-Id: I49cb276827f4a06791183ee3fe8c88ba84df085d
CRs-Fixed: 2791341

dp/inc/cdp_txrx_mon_struct.h

@@ -229,6 +229,8 @@ enum {
  *  mointor status and monitor destination ring
  * @status_ppdu_drop: Number of ppdu dropped from monitor status ring
  * @dest_ppdu_drop: Number of ppdu dropped from monitor destination ring
+ * @mon_link_desc_invalid: msdu link desc invalid count
+ * @mon_rx_desc_invalid: rx_desc invalid count
  */
 struct cdp_pdev_mon_stats {
 #ifndef REMOVE_MON_DBG_STATS
@@ -257,5 +259,7 @@ struct cdp_pdev_mon_stats {
 	uint32_t ppdu_id_match;
 	uint32_t status_ppdu_drop;
 	uint32_t dest_ppdu_drop;
+	uint32_t mon_link_desc_invalid;
+	uint32_t mon_rx_desc_invalid;
 };
 #endif