There is nothing in this environment variable that cannot
be done better with -d flags.  There is nothing special
about TCI that warrants this hack.

Moreover, it does not compile -- remove it.

Reported-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>