libplayer: propagate 'depends on' from mplayer
BR2_PACKAGE_LIBPLAYER_MPLAYER should not select BR2_PACKAGE_MPLAYER
without having the 'depends on' that BR2_PACKAGE_MPLAYER has.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>