Bluetooth: btbcm: disable read tx power for MacBook Air 8,1 and 8,2

commit 3318ae23 upstream.

The MacBook Air 8,1 and 8,2 also need querying of LE Tx power
to be disabled for Bluetooth to work.

Signed-off-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>