Add BT_POWER socket option.

BT_POWER socket option is used to control the power
characteristics of the underlying ACL link. Currently, this is
used to set the ACL link to active mode when the remote end has put
the ACL link in sniff mode and we are sending data. By default,
the ACL link will always be moved to active mode. However, this
causes problems with HID devices. And hence, for HID devices the
ACL link will not be moved to active mode when we are sending data.

This socket option is implemented for both rfcomm and l2cap sockets.

Change-Id: I0261a8daa2241d691670cc690cd27c39c67c1591
5 files changed