driconf: avoid Non-ASCII character error in driconf_static.py

driconf: avoid Non-ASCII character error in driconf_static.py

MR to move to python3 in Android build gen rules is still pending

The change is to avoid following building error:

FAILED: out/target/product/x86_64/gen/STATIC_LIBRARIES/libmesa_util_intermediates/driconf_static.h
/bin/bash -c "/usr/bin/python external/mesa/src/util/driconf_static.py external/mesa/src/util/00-mesa-defaults.conf > out/target/product/x86_64/gen/STATIC_LIBRARIES/libmesa_util_intermediates/driconf_static.h"
  File "external/mesa/src/util/driconf_static.py", line 2
SyntaxError: Non-ASCII character '\xc2' in file external/mesa/src/util/driconf_static.py on line 2, but no encoding declared; see http://python.org/dev/peps/pep-0263/ for details

Fixes: a6b0ceb ("driconf: Generate a static table when no xmlconfig")
Acked-by: Rob Clark <robclark@freedesktop.org>
Tested-by: Marijn Suijten <marijn.suijten@somainline.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9294>