Implement local LE features adapter property

Implement local LE features adapter property

This patch handles Adapter's local LE features property
which will indicate whether adapter supports LE 2M PHY
and LE CODED PHY. This property is emitted by bluetoothd
as adapter's property changed event and handled in
bluetooth HAL layer. LE features are further propagated to
bt-service via new OAL event OAL_EVENT_BLE_LOCAL_FEATURES.
LE features will be finally saved in bt-service daemon.
Application can read these values directly from bt-service.

Change-Id: I9e1b617851693b7bab038a9f10861c6bf3ba8835
Signed-off-by: Anupam Roy <anupam.r@samsung.com>