qcacmn: Add rx_errors stats

Update rx error stats. It is a summation of below failures:
 - desc_alloc_failure [No free desc available]
 - csum error [IP/TCP_UDP]
These failure stats are updated at pdev level and no need
to aggregate this.Directly add at pdev level and export.

Change-Id: I0a5fa8f972babf092163f3cb2d0093547ded4877
CRs-Fixed: 2496037

dp/inc/cdp_txrx_cmn_struct.h

@@ -1396,6 +1396,7 @@ struct cdp_tx_completion_ppdu {
  * @tx_dropped: Tx dropped is same as tx errors as above
  * @rx_packets: Rx total packets transmitted
  * @rx_bytes  : Rx total bytes transmitted
+ * @rx_errors : Rx erros
  */
 struct cdp_dev_stats {
 	uint32_t tx_packets;
@@ -1404,6 +1405,7 @@ struct cdp_dev_stats {
 	uint32_t tx_dropped;
 	uint32_t rx_packets;
 	uint32_t rx_bytes;
+	uint32_t rx_errors;
 };
 
 /**