I apologize for the late reply, but there was a technical issue on the forum, and we have not seen this post until now.
The GPIO driver that you installed is the GPIO controller driver.
You need to write a driver for your specific device, this driver interacts with the GPIO Controller using the GPIOClx.
This is a decision of Microsoft, not an Intel decision, so we can't comment about why it is done this way.
This page provides more information: