MAINTAINERS: update my entries

Acked-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Josh de Kock <josh@itanimul.li>

MAINTAINERS

@@ -285,6 +285,7 @@ libavdevice
   pulse_audio_enc.c                     Lukasz Marek
   qtkit.m                               Thilo Borgmann
   sdl                                   Stefano Sabatini
+  sdl2.c                                Josh de Kock
   v4l2.c                                Giorgio Vazzana
   vfwcap.c                              Ramiro Polla
   xv.c                                  Lukasz Marek