buildscripts: disable ffmpeg devices too
buildscripts: disable ffmpeg devices too

avoids a compiler error inside libavdevice/v4l2.c with clang

jeeb/mpv-android,mpv-android/mpv-android,mpv-android/mpv-android,mpv-android/mpv-android,mpv-android/mpv-android,jeeb/mpv-android,jeeb/mpv-android,mpv-android/mpv-android,jeeb/mpv-android,jeeb/mpv-android