turnip: Add a .editorconfig and .dir-locals.el

I was inheriting the one from src/freedreno with funny tabs, while
this driver is written with normal Mesa 3-space indents.
Unfortunately I have to add both files, because I use emacs and emacs
prefers .dir-locals to .editorconfig :(

Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
3 files changed