radeonsi: remove emacs style config file

As radeonsi has synced the code style with main mesa,
remove the orginal radeonsi spec emacs config file and
use the top level dir .dir-locals.el

Acked-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4961>
1 file changed