* gnu/packages/audio.scm (webrtc-audio-processing)[arguments]: Adjust
custom arguments list to also fix building on all powerpc architectures.
[native-inputs]: Add patch, local-file on riscv64-linux and powerpc
architectures.
* gnu/packages/patches/webrtc-audio-processing-big-endian.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
