[PATCH] ata: Don't use NO_IRQ in pata_of_platform driver

[Alan Cox]

> can we sinply introduce a macro irq_is_valid

See the 2005, 2006 and 2008 discussion.

    if (!dev->irq)

is the proper test.

The <= is just a temporary thing while ARM gets its publically visible
house in order so it can be done without breakage.

Alan