serial: Kill off NO_IRQ

We transform the offenders into a test of irq <= 0 which will be ok while
the ARM people get their platform sorted. Once that is done (or in a while
if they don't do it anyway) then we will change them all to !irq checks.

For arch specific drivers that are already using NO_IRQ = 0 we just test
against zero so we don't need to re-review them later.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index e9c2dfe4..08ebe90 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -1506,7 +1506,7 @@
 	 * fixed up interrupt info, but we use the device-tree directly
 	 * here due to early probing so we need the fixup too.
 	 */
-	if (uap->port.irq == NO_IRQ &&
+	if (uap->port.irq == 0 &&
 	    np->parent && np->parent->parent &&
 	    of_device_is_compatible(np->parent->parent, "gatwick")) {
 		/* IRQs on gatwick are offset by 64 */