qcacmn: Free pdev configuration parameters during pdev detach

Free the memory allocated for the pdev configuration parameters
during pdev detach so that there are no memory leaks

Change-Id: I856cc6e6082197e98ad105053f1e4cffc2d25c53
CRs-Fixed: 2444000

wlan_cfg/wlan_cfg.c

@@ -365,7 +365,8 @@ struct wlan_cfg_dp_pdev_ctxt *wlan_cfg_pdev_attach(void *psoc)
 
 void wlan_cfg_pdev_detach(struct wlan_cfg_dp_pdev_ctxt *wlan_cfg_ctx)
 {
-	qdf_mem_free(wlan_cfg_ctx);
+	if (wlan_cfg_ctx)
+		qdf_mem_free(wlan_cfg_ctx);
 }
 
 void wlan_cfg_set_num_contexts(struct wlan_cfg_dp_soc_ctxt *cfg, int num)