qcacld-3.0: avoid conditional compilation for HEADROOM_SIZE macro

qcacld-2.0 to qcacld-3.0 propagation
In hdd_alloc_station_adapter, deleted pWlanDev->hard_header_len updating
code.

Change-Id: I7a3ead434a910dd522f9a02a24cd6ad8669e3fc8
CRs-Fixed: 853305

core/hdd/inc/wlan_hdd_main.h

@@ -79,8 +79,6 @@
 /** Length of the TX queue for the netdev */
 #define HDD_NETDEV_TX_QUEUE_LEN (3000)
 
-/** Bytes to reserve in the headroom */
-#define LIBRA_HW_NEEDED_HEADROOM   128
 /** Hdd Tx Time out value */
 #ifdef LIBRA_LINUX_PC
 #define HDD_TX_TIMEOUT          (8000)

core/hdd/src/wlan_hdd_main.c

@@ -1815,7 +1815,6 @@ static hdd_adapter_t *hdd_alloc_station_adapter(hdd_context_t *hdd_ctx,
 		cdf_mem_copy(adapter->macAddressCurrent.bytes, macAddr,
 			     sizeof(tSirMacAddr));
 		pWlanDev->watchdog_timeo = HDD_TX_TIMEOUT;
-		pWlanDev->hard_header_len += LIBRA_HW_NEEDED_HEADROOM;
 
 		if (hdd_ctx->config->enable_ip_tcp_udp_checksum_offload)
 			pWlanDev->features |=