x230t : add hotp/non-hotp variant and specialized coreboot config, add x230t to BOARD_TESTERS.md

[tlaurion]

Might close #1744

---

• x230t do not suffer from backspace and pipe keyboard issues since coreboot 24.02.01 + current 5.10.5 kernel used in master
• x230t soundcard doesn't work
• power button doesn't work

If this PR fixes x230t issues preventing x230t to be used by flashing x230 roms, cool.

Otherwise forget about x230t or deal with upstream coreboot and never talk about x230t or keyboard issues on old Thinpads tablet models until fixed upstream. Wil I do the same for x220t and other tablets? No. The trail below should suffice to any non-developer to create board variants. It's not coding, its porting: this is about plugging things together, not even understanding how things work under the hood. Nonetheless to say: more testers are needed for such boards in case something technical needs to be investigated: I won't have the time to do it if it doesn't work.

For more details, see all linked issues to #1744

Repro for anyone wanting to create a specialized board config pointing to a specialized coreboot/linux config file for a board variant. x230t is x230 but pointing to a different coreboot config file. This is all that is different, se file changes of this PR:

#do branch for commit
git checkout -b x230t_addition
#copy/move x230 boards and rename to x230t
cp -r boards/x230-maximized/ boards/x230t-maximized cp -r boards/x230-hotp-maximized boards/x230t-hotp-maximized mv boards/x230t-hotp-maximized/x230-hotp-maximized.config boards/x230t-hotp-maximized/x230t-hotp-maximized.config mv boards/x230t-maximized/x230-maximized.config boards/x230t-maximized/x230t-maximized.config cp config/coreboot-x230-maximized.config config/coreboot-x230t-maximized.config vim boards/x230t-maximized/x230t-maximized.config
#point boards to x230t to be modified coreboot config file
vim boards/x230t-hotp-maximized/x230t-hotp-maximized.config 
# call Heads coreboot Makefile helper to modify coreboot config with menuconfig in place
docker run -e DISPLAY=$DISPLAY --network host --rm -ti -v $(pwd):$(pwd) -w $(pwd) tlaurion/heads-dev-env:latest -- make BOARD=x230t-maximized coreboot.modify_and_save_oldconfig_in_place 
#Add board configs and coreboot config changes in to be git commit
git add boards/x230t-hotp-maximized/x230t-hotp-maximized.config boards/x230t-maximized/x230t-maximized.config config/coreboot-x230t-maximized.config 
#add x230t board names to be built by CircleCI by this commit
vim .circleci/config.yml
git add .circleci/config.yml
#Add @fhvyhjriur to x230t board testers in tracking file
vim BOARD_TESTERS.md
git add BOARD_TESTERS.md
#create git commit, signing commit with message
git commit --signoff -m
#push this commit to a PR.
git push --force tlaurion-github

@fhvyhjriur please test and report...

[tlaurion]

Only difference between x230 and x230t:

user@heads-tests-deb12-nix:~/heads$ diff config/coreboot-x230t-maximized.config config/coreboot-x230-maximized.config 
196,197c196,197
< # CONFIG_BOARD_LENOVO_X230 is not set
< CONFIG_BOARD_LENOVO_X230T=y
---
> CONFIG_BOARD_LENOVO_X230=y
> # CONFIG_BOARD_LENOVO_X230T is not set