qcacld-3.0: SAP Rx: get sta_id for dhcp packet only

Check for dhcp packet type before processing on packet sta_id.
This reduces per packet mem_copy and mem_cmp instructions for
sap Rx.

Change-Id: I4a2732ff4d9e3fa31aace25cc824f26b0c339b52
CRs-Fixed: 2331420

core/hdd/src/wlan_hdd_ipa.c

@@ -401,7 +401,8 @@ void hdd_ipa_send_skb_to_network(qdf_nbuf_t skb, qdf_netdev_t dev)
 		return;
 	}
 
-	if (adapter->device_mode == QDF_SAP_MODE) {
+	if ((adapter->device_mode == QDF_SAP_MODE) &&
+	    (qdf_nbuf_is_ipv4_dhcp_pkt(skb) == true)) {
 		/* Send DHCP Indication to FW */
 		struct qdf_mac_addr *src_mac =
 			(struct qdf_mac_addr *)(skb->data +