TS35 / Generic SPI screen support?

Hello!

Is there a possibility to connect [TS35 touch screen](https://github.com/makerbase-mks/MKS-TFT-Hardware/tree/master/MKS%20TS35-R/MKS%20TS35-R%20V2.0_002)? If I understand it correctly, it's a SPI-based screen, so in theory it should be compatible with CB1 since it's not a DPI one. I tried to follow a [guide made for raspberry pi](https://github.com/fbeltrao-br/mksts35) to set up KlipperScreen, but encountered some issues, mainly being:
1. In the guide they used a dtoverlays called `tinylcd35` and `touch`, but there are no such overlays in CB1 (it seems). I am not quite familiar with device tree overlays, but in my understanding they define a hardware device by its pins and features. Is it possible to make those overlays or copy them from rpi install? I think they will require some changes...
2. While building `fbcp`, I got some compile errors related with some headers that should be a part of couple packages, but they are not in the repos, it seems. I didn't pay much attention to this, since without P.1 it's useless anyway.

I've found 3 possibly interesting CB1 overlays called `tft35_spi`, `mcp2515` and `spi-spidev`, they all are related to SPI operation, but I'm afraid they will not work as expected in the guide in its current form. First one is made for [BTT's SPI screen](https://biqu.equipment/products/bigtreetech-tft35-spi-v2-1-touchscreen-io2can-module), which uses I2C touch control, and it seems TS35 uses SPI for touch as well, so I'm not sure.

Maybe somebody had some experience with all of those, or even connected a SPI screen to CB1?

Thank you.

Start with the CB1 overlays named tft35_spi, mcp2515, and spi-spidev, then compare them with the tinylcd35 and touch overlays used by the linked Raspberry Pi guide. Check whether the TS35 display and touch interface match the available SPI configuration, and investigate the reported fbcp package and header errors. Done means documenting or implementing a viable CB1 setup for the display, including working touch support.

Written by the indexing model from the issue text.