LE Data Packet Extension support

Included support for LE data packet extension feature according
to BT 4.2 spec. This patch checks if the controller supports LE
packet extension and provides functions to set the PDU length.

Bug: 20013956
Change-Id: I6a92970fede2f793ad48c9fa2e0247ad00297533
diff --git a/bta/include/bta_api.h b/bta/include/bta_api.h
index e6de6bb..9c13be4 100644
--- a/bta/include/bta_api.h
+++ b/bta/include/bta_api.h
@@ -2146,6 +2146,17 @@
 
 /*******************************************************************************
 **
+** Function         BTA_DmBleSetDataLength
+**
+** Description      This function is to set maximum LE data packet size
+**
+** Returns          void
+**
+*******************************************************************************/
+extern void BTA_DmBleSetDataLength(BD_ADDR remote_device, UINT16 tx_data_length);
+
+/*******************************************************************************
+**
 ** Function         BTA_DmBleSetStorageParams
 **
 ** Description      This function is called to set the storage parameters