commit 646907f5 upstream.

Added support to the ftdi_sio driver for ekey Converter USB which
uses an FT232BM chip.
Signed-off-by: Jaša Bartelj <jasa.bartelj@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>