A bunch of GPIO fixes for the v4.7 series:

- Drop the lock before reading out the GPIO direction
  setting in drivers supporting the .get_direction()
  callback: some of them may be slowpath.

- Flush GPIO direction setting before locking a GPIO as an
  IRQ: some electronics or other poking around in the
  registers behind our back may have happened, so flush
  the direction status before trying to lock the line for
  use by IRQs.

- Bail out silently when asked to perform operations on
  NULL GPIO descriptors. That is what all the get_*_optional()
  is about: we get optional GPIO handles, if they are not
  there, we get NULL.

- Handle compatible ioctl() correctly: we need to convert
  the ioctl() pointer using compat_ptr() here like everyone
  else.

- Disable the broken .to_irq() on the LPC32xx platform.
  The whole irqchip infrastructure was replaced in the
  last merge window, and a new implementation will be
  needed.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
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=5IlZ
-----END PGP SIGNATURE-----