qcacmn: Add changes to update band info in txrx_peer NULL case

Currently if txrx_peer is NULL in Tx completion or rx process
band update will not happen, which will result in invalid band
issue during connectivity logging.

To fix the issue maintain local link id and use link id to
find link peer and update band information in nbuf cb
based on peer frequency.

Change-Id: Ia5a6001fbc167a497660dc7be39a3e641dd28896
CRs-Fixed: 3654696

dp/wifi3.0/dp_peer.h

@@ -65,6 +65,14 @@ enum dp_bands {
 	DP_BAND_6GHZ = 3,
 	DP_BAND_UNKNOWN = 4,
 };
+
+/**
+ * dp_freq_to_band() - Convert frequency to band
+ * @freq: peer frequency
+ *
+ * Return: band for input frequency
+ */
+enum dp_bands dp_freq_to_band(qdf_freq_t freq);
 #endif
 
 void check_free_list_for_invalid_flush(struct dp_soc *soc);