So, do you want media_build drivers to be _compiled_ during build process, or just included?
media_build is tricky to build reproduceably, as it pulls latest sources from the upstream tree,
while beeing quite slow in adapting its supplied backport-patches, which frequently breaks it
for example, a new source tar is up since friday, with it fails at apply patches stage
but manually wget'ing and untaring the previous one will work normally
also, some drivers wont compile for arm even if seemingly supported by the kernel
so we would need to "freeze" a working media_build+linux-media combo and fork it somewhere