There are targets which neither have usb host nor pci support but do have audio
capabilities. Those targets should expliclitly specifiy that they support audio
through the new feature flag. The audio feature flag is also implicitly selected
by the usb and pci feature flags.


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@19643 3c298f89-4303-0410-b956-a3cf2f4a3e73