qcacmn: Add new set and get APIs to manage cfg items

Add new set and get APIs for cfg items so that
those cfg items can be managed from the external
components.

Change-Id: I52eb747fc6c544cfe43273c3b8b0fcc27b5a4a5f
CRs-Fixed: 3502582

dp/wifi3.0/dp_rx_buffer_pool.c

@@ -295,7 +295,8 @@ static void dp_rx_refill_buff_pool_init(struct dp_soc *soc, u8 mac_id)
 		return;
 	}
 
-	buff_pool->max_bufq_len = DP_RX_REFILL_BUFF_POOL_SIZE;
+	buff_pool->max_bufq_len =
+		wlan_cfg_get_rx_refill_buf_pool_size(soc->wlan_cfg_ctx);
 	buff_pool->dp_pdev = dp_get_pdev_for_lmac_id(soc, 0);
 	buff_pool->tail = 0;