gpio: max732x: Fix irq-events handler
gpio: max732x: Fix irq-events handler

MAX732X clears all pending interrupts on I2C read (when interrupts
register is being read). Driver doesn't need to send any ACKs when
interrupt was handled. So replace handle_edge_irq() with
handle_simple_irq().

Using handle_edge_irq() (w/o .irq_ack callback set) may lead to NULL
pointer dereference in some cases. E.g. this was observed on
hibernation process:

  Unable to handle kernel NULL pointer dereference at virtual address 0
  Backtrace:
  (handle_edge_irq) from (resend_irqs)
  (resend_irqs) from (tasklet_action)
  (tasklet_action) from (__do_softirq)
  (__do_softirq) from (run_ksoftirqd)
  (run_ksoftirqd) from (smpboot_thread_fn)
  (smpboot_thread_fn) from (kthread)
  (kthread) from (ret_from_fork)

Signed-off-by: Semen Protsenko <e3e0098ede0001339d6139e93917c216f5e40eec@globallogic.com>
Reviewed-by: Grygorii Strashko <bfa0a1520768723a1c60e18250fb841c342eb8d8@linaro.org>
Signed-off-by: Linus Walleij <9cd9d802d23c0ed5e224beabf4ae4a5c478746ef@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs