portaudio: explicitly disable oss, add PACKAGECONFIG for alsa and jack

* autoenabled dependencies on alsa-lib and jack are breaking espeak
  when it's built against portaudio in sysroot without them
  | ld: warning: libasound.so.2, needed by usr/lib/libportaudio.so, not found (try using -rpath or -rpath-link)
  | ld: warning: libjack.so.0, needed by usr/lib/libportaudio.so, not found (try using -rpath or -rpath-link)
  | usr/lib/libportaudio.so: undefined reference to `snd_pcm_sw_params_sizeof@ALSA_0.9'
  | usr/lib/libportaudio.so: undefined reference to `snd_pcm_hw_params_test_period_size@ALSA_0.9'

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>