Clean up Mitemp_bt constants

[tkdrob]

Breaking change

Proposed change

Clean up Mitemp_bt.

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[cgarwood]

Just need to rebase/remove the commit for acer_projector in the PR 🙂

[cgtobi]

LGTM

[frenck]

There is an unrelated commit in this PR. Please git rebase to clean it up.

[cgtobi]

@frenck that acer_projector change? I guessed it was part of his whole effort to clean up constants.

[frenck]

@cgtobi That commit was part of #46880 and leaked into this branch.

[cgtobi]

Ah, well spotted. I didn't cross check that. 👍