[IRDA]: nsc-ircc: ISAPnP support

This enables PnP support for the nsc-ircc chipset.
Since we can't fetch the chipset cfg_base from the PnP layer, we just use
the PnP information as one more hint when probing the chip.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
Signed-off-by: Samuel Ortiz <samuel.ortiz@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>