lynxpoint: Expose ACPI Device for LP GPIO controller

In order to probe the gpio-lynxpoint kernel driver the
LP GPIO controller needs to be exposed as a specific
ACPI device.

This also allows the resources to be exposed to the OS via
this device instead of the catch-all LPC device.

BUG=chrome-os-partner:19255
TEST=manual:

Ensure the driver loads at boot:
gpiochip_find_base: found new base at 162
gpiochip_add: registered GPIOs 162 to 255 on device: INT33C7:00

Also ensure the driver is visible in sysfs:
$ cat /sys/devices/platform/INT33C7:00/gpio/gpiochip162/label
INT33C7:00

Change-Id: I9f79c008f88da9b67ed1cdfdb9d3a581ce8f05ff
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/50215
2 files changed