Bluetooth: BAP: Use def_bool instead of select for BT_AUDIO_RX/TX

Remove the selects and use  def_bool for BT_AUDIO_RX and
BT_AUDIO_TX.

This is part of an effort to reduce select in Kconfig.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>
3 files changed