contrib: gitdm: add more individual contributors

contrib: gitdm: add more individual contributors

I know Richard's is right because I asked him in the pub. I'm guessing
Fredrik's based on the fact I vaguely remember an Atari demo. The
others I attributed to academic institutions last time I posted so
have moved them to individuals as requested.

Cc: Fredrik Noring <noring@nocrew.org>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Richard Henderson <rth@twiddle.net>