MAINTAINERS: add myself to mediacodec

Signed-off-by: Matthieu Bouron <matthieu.bouron@gmail.com>

MAINTAINERS

@@ -268,7 +268,7 @@ Hardware acceleration:
   crystalhd.c                           Philip Langdale
   dxva2*                                Hendrik Leppkes, Laurent Aimar, Steve Lhomme
   d3d11va*                              Steve Lhomme
-  mediacodec*                           Matthieu Bouron
+  mediacodec*                           Matthieu Bouron, Aman Gupta
   vaapi*                                Gwenole Beauchesne
   vaapi_encode*                         Mark Thompson
   vdpau*                                Philip Langdale, Carl Eugen Hoyos