smsc-ircc2: add PNP support

smsc-ircc2: add PNP support

Claim devices using PNP, unless the user explicitly specified device
addresses.  This can be disabled with the "smsc-ircc2.nopnp" option.

This removes the need for probing legacy addresses and helps untangle IR
devices from serial8250 devices.

Sometimes the SMC device is at a legacy COM port address but does not use the
legacy COM IRQ.  In this case, claiming the device using PNP rather than 8250
legacy probe means we can automatically use the correct IRQ rather than
forcing the user to use "setserial" to set the IRQ manually.

If the PNP claim doesn't work, make sure you don't have a setserial init
script, e.g., /etc/init.d/setserial, configured to poke in legacy COM port
resources for the IRDA device.  That causes the serial driver to claim
resources needed by this driver.

Based on this patch by Ville Syrjälä:
    http://www.hpl.hp.com/personal/Jean_Tourrilhes/IrDA/ir260_smsc_pnp.diff

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Keith Owens <kaos@ocs.com.au>
Cc: Len Brown <lenb@kernel.org>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: Matthieu CASTET <castet.matthieu@free.fr>
Cc: Jean Tourrilhes <jt@hpl.hp.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Ville Syrjala <syrjala@sci.fi>
Cc: Russell King <rmk+serial@arm.linux.org.uk>
Acked-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>