pinctrl: cherryview: Add support for GMMR GPIO opregion

On some Cherry Trail devices the ASL uses the GMMR GPIO to access
GPIOs so as to serialize MMIO accesses to GPIO registers with the
OS, because:

"Due to a silicon issue, a shared lock must be used to prevent concurrent
accesses across the 4 GPIO controllers.

See Intel Atom Z8000 Processor Series Specification Update (Rev. 005),
errata #CHT34, for further information."

This commit adds support for this opregion, this fixes a number of
ASL errors on my Ezpad mini3 tablet and makes the otg port device/host
muxing which is controlled in firmware on this model work properly.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>