i2c/generic: Allow GPIOs to be put in _CRS and PowerResource in ACPI

Linux kernel expects that power management with ACPI should always be
handled using PowerResource. However, some kernel drivers (e.g. ELAN
touchscreen) check to see if reset gpio is passed in by the BIOS to
decide whether the device loses power in suspend. Thus, until the kernel
has a better way for drivers to query if device lost power in suspend,
we need to allow passing in of GPIOs via _CRS as well as exporting
PowerResource to control power to the device.

Update mainboards to export reset GPIO as well as PowerResource for
ELAN touchscreen device.

TEST=Verified that touchscreen works on power-on as well as after

Change-Id: I3409689cf56bfddd321402ad5dda3fc8762e6bc6
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/18238
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
5 files changed