serial: 8250: don't bind to SMSC IrCC IR port

commit ffa34de0

 upstream.

SMSC IrCC SIR/FIR port should not be bound to by
(legacy) serial driver so its own driver (smsc-ircc2)
can bind to it.

Signed-off-by: Maciej Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>