[configure] fix goldlinker check
[rbp/omxplayer] Explicitly set number of output channels on audio_mixer
Merge pull request #2939 from popcornmix/fix_downmix

[rbp/omxplayer] Explicitly set number of output channels on audio_mixer
Merge pull request #2937 from wsnipex/configure

[configure] fix goldlinker check (closes #13647)