dts:arm64:seco: Add atmel_mxt touch to pbb, refactor devicetree include tree for cap touch

The touch is connected to a different port and other RESET gpio then on other platform combinations. To handle this a 'cap_touch' node is inserted at baseboard level, configuring gpios and bus. The driver compatible is set in the display dtsi. This way the abstraction follows the hardware, using only dtc features ( not C MACROS).

BCS 746-001108