Subject: [bug#39719] FFmpeg library preference for dav1d

From: Leo Famulari <[email-masked]>
Date: Fri, 21 Feb 2020 12:34:53 -0500

This patch, taken from upstream FFmpeg, reorders the library
dependencies in FFmpeg so that the more performant dav1d is preferred
over libaom.

This patch supersedes <https://bugs.gnu.org/39714>.