NET: smc91x: Fix irq flags

smc91x.h defines SMC_IRQ_FLAGS to be -1 when it wants the interrupt
flags to be taken from the resource structure.  However, d280eadc


changed this to checking for non-zero resource flags.

Unfortunately, this means that on some platforms, we end up passing
'-1' to request_irq rather than the desired result.  Combine the two
conditions into one so that the IRQ flags are taken from the resource
if either SMC_IRQ_FLAGS is -1 or the resource flags specify an
interrupt trigger.

This restores network on at least the Versatile platform.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>