The only supported interface to the ALSA 5 drivers is through libasound.so. Direct use of ioctl()'s aren't supported because of the requirements of the ALSA API. It uses ioctl()'s in ways that are illegal in the QNX OS (e.g. passing a structure that contains a pointer through an ioctl()).
The asound library is licensed under the Library GNU Public License (LGPL). This means that any changes to the library must be open-sourced, but proprietary code can link to the library without becoming open-source.
The asound library is released with QNX only as a shared library (libasound.so). QNX Software Systems won't be offering a static library. The intention is to gradually improve the quality and number of services that this library provides; by linking against shared libraries, you'll receive the benefits of improvements without recompiling.