qcacld-3.0: enable DP pending memory flushing

Enable DP pending memory flushing by macro WLAN_DP_PENDING_MEM_FLUSH

Change-Id: I77a85c208a77cf7d2e43270b396e4ed9e41c3e85
CRs-Fixed: 2543465
diff --git a/configs/default_defconfig b/configs/default_defconfig
index 1363f0c..7a52bdd 100644
--- a/configs/default_defconfig
+++ b/configs/default_defconfig
@@ -854,6 +854,7 @@
 	CONFIG_WLAN_DP_PER_RING_TYPE_CONFIG := y
 	#Enable WMI TX/RX over QMI
 	CONFIG_WMI_SEND_RECV_QMI := y
+	CONFIG_WLAN_DP_PENDING_MEM_FLUSH := y
 endif
 
 #Flag to enable hdd memory dump feature