package/mpv: link with libatomic if needed
Fixes:
- http://autobuild.buildroot.org/results/12f4580429427b6b546184366f74da16f83d692c
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 71cb0f0f722875100cd18df9484a7a30f53bfbeb)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>