As a part of BT 4.1 stack upgrade, added host support for BR/EDR
secure connections to be able to interact with controllers that
support secure connections and upgrade the SSP mechanism to use
secure connection rules.

This change checks for controller support in the extended_features
(LMP page 2) and then declares the host support (extended_features
LMP page 1) using WRITE SECURE CONNECTIONS HOST SUPPORT.
If both the sides support secure connections, the simple pairing
process utilizes the link key generated using P-256 elliptic curve
(in the controller) and both the sides will be
in a secure connection.

Bug: 19289699
Change-Id: Idb3c41f439973bea137f5a4a69468c1f55aecbd7