bluetooth : Configure the Tx idle timeout to 1sec

when there is no activity on the host tx for 1 sec
indicate the controller to enter into sleep.
1sec is the optimal value we need to satisfy the power
and performance requirements.

Change-Id: I9c2a2973a7fbb1a49460e06117c264aa4e0e44e4
Signed-off-by: Anantha Krishnan <ananthk@codeaurora.org>