package/pulseaudio: fix musl build

Fixes build errors in previous version which are still present
http://autobuild.buildroot.net/results/879/879260f0efc80c2c9061d89d3e99ad107083f72a/
http://autobuild.buildroot.net/results/1e5/1e5f6a5f349800226d8b07601dab68ffe7794461/
http://autobuild.buildroot.net/results/0f8/0f8d68b11c6807a9d1d4c40a66430ac096902720/



Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Reviewed-by: Romain Naour <romain.naour@gmail.com>

[Thomas:
 - Rework patch 0001-padsp-Make-it-compile-on-musl.patch to put
   Bernd's comment and SoB *after* the original commit log.
 - Rework patch 0002-musl-fixes.patch for the same reason, and also to
   remove the xlocale.h part, which has already been fixed upstream.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>