Add missing entry for maintainer of rtpenc_hevc.*

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

MAINTAINERS

@@ -463,7 +463,7 @@ Muxers/Demuxers:
   rtmp*                                 Kostya Shishkov
   rtp.c, rtpenc.c                       Martin Storsjo
   rtpdec_h261.*, rtpenc_h261.*          Thomas Volkert
-  rtpdec_hevc.*                         Thomas Volkert
+  rtpdec_hevc.*, rtpenc_hevc.*          Thomas Volkert
   rtpdec_asf.*                          Ronald S. Bultje
   rtpenc_mpv.*, rtpenc_aac.*            Martin Storsjo
   rtsp.c                                Luca Barbato