On tosa the tranciver LED isn't powered down if
the GPIO47 (STUART_TX) isn't configured as low-level.
Power it down if IrDA is off to save a bit of power.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>