irqchip: bcm7120-l2: Eliminate bad IRQ check

irqchip: bcm7120-l2: Eliminate bad IRQ check

This check may be prone to race conditions, e.g.

1) Some external event (e.g. GPIO level) causes an IRQ to become pending
2) Peripheral asserts the L2 IRQ
3) CPU takes an interrupt
4) The event from #1 goes away
5) bcm7120_l2_intc_irq_handle() reads back a 0 status

Unlike the hardware supported by brcmstb-l2, the bcm7120-l2 controller
does not latch the IRQ status.  Bits can change if the inputs to the
controller change.  Also, do_bad_IRQ() is an ARM-specific macro.

So let's just nuke it.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lkml.kernel.org/r/1415342669-30640-7-git-send-email-cernekee@gmail.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>