package/mpd-mpc: disable documentation
Disable documentation which is available (and enabled by default) since
bump to version 0.31 in commit 0186da2923c07656005264dbb3001ca706a2ef10
and
https://github.com/MusicPlayerDaemon/mpc/commit/60e173c0198743fd6af906682eadec1cc67a4975
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>