HID: bpf: Add support for the XP-PEN Deco Mini 4

The XP-PEN Deco Mini 4 is a UGEE device with a frame with 6 buttons. Its pen has 2 buttons and supports pressure reporting.

Fix their report descriptors and transform the frame button events to support it.

For reference/testing, here are some easy to understand hid-recordings of the device:

01-pad-buttons.txt
02-pad-buttons-combined.txt
03-pen-left-to-right.txt
04-pen-top-to-bottom.txt
05-pen-pressure.txt
06-pen-buttons-bottom-up.txt
07-raw-event-node.txt

Related links:

• libwacom: https://github.com/linuxwacom/libwacom/pull/705
• Wacom HID descriptors: https://github.com/linuxwacom/wacom-hid-descriptors/issues/386