qcacld-3.0: Enable TX_AGGREGATION_SIZE_ENABLE for HST

Tx MPDU aggregation is not happening in HE80 11ax connection
resulting in low throughput for HST.

Fix is to enable TX_AGGREGATION_SIZE_ENABLE for HST.

Change-Id: Ieca8464991a6a194d6f02b70fe4972aca288b541
CRs-Fixed: 2925514

Kbuild

@@ -3446,6 +3446,10 @@ cppflags-y += -DDP_MON_RSSI_IN_DBM
 cppflags-y += -DSYSTEM_PM_CHECK
 endif
 
+ifeq ($(CONFIG_TX_AGGREGATION_SIZE_ENABLE), y)
+cppflags-y += -DTX_AGGREGATION_SIZE_ENABLE
+endif
+
 # Enable Low latency optimisation mode
 cppflags-$(CONFIG_WLAN_FEATURE_LL_MODE) += -DWLAN_FEATURE_LL_MODE