bluesleep: Don't wait for uart tx queue to flush

* UART tx queue created rare issues of BT resetting due to some error.
* This patch will help entering lpm faster.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
defconfig: remove junk

Let's keep just franco, hammerhead and msm8974 defconfigs.
I'll probably rename franco_defconfig someday since this kernel it's a little detached from Franco's original work.