Add touch polarity

In the past we used a devicetree append mechanism in the XML setting to manipulate eh device tree setting of the touch nodes. Especially the EXC3000 and the EDT touches needed this.

We do not want to include this feature to gfxml2dto because the kind of XML overlays cannot be generally applied.

There was, however, previously a first shot adding a special irq-gpio node to the touch XML node instead. This makes it more XML description like however limited the use to just IRQs.

This patch set adds the reset and wake GPIO as well and uses the tags to determine the polarity.