drivers/misc/ti-st: chip_disable on timeout

If the communication with the WiLink breaks down for whatever reasons & the
ti-st driver is unable to un-install the line-discipline during clean-up in
st_kim_stop, the GPIO should be held low (BT_EN=0) & the platform's chip
disable hook shall also be called.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>