Please collect data from /sys/firmware/devicetree/base/

[bdrung]

Raspberry Pis and other SBCs (like Odroid) expose their device tree in /sys/firmware/devicetree/base/. They contain data like model that expose the hardware model (similar to the node_dmi_info collector).

Proposal: add a devicetree collector that reads:

• /sys/firmware/devicetree/base/name (empty on my systems)
• /sys/firmware/devicetree/base/model (example: Raspberry Pi Zero W Rev 1.1)
• /sys/firmware/devicetree/base/compatible (example: raspberrypi,model-zero-wbrcm,bcm2835)
• /sys/firmware/devicetree/base/serial-number (example: 16 digit hex string)

And expose those data in node_devicetree_info.