hwmodels: adding separate file in the driver kit to handle queries

Signed-off-by: Reto Achermann <reto.achermann@inf.ethz.ch>

ioat driver: returing actual error value instead of SYS_ERR_OK.

libdma: service initialization with user supplied argument

added the possibility to give the service initialization and the connect
callback a user specified argument to hand over some state when a new
client connects and the connect callback is executed.

libdma: refactoring of driver client as a "virtual" dma device

The DMA clients are now acting as a "normal" dma device where the
requests are forwared to the DMA driver service domain instead of
serving locally. The client initializes a DMA device by service name,
iref or supported memory range.

Extended the DMA manager to serve iref based queries.

Several generalizations of some device/channel functions to handle the
requests and forward them to the specific functions.

Adapted the dma_test domain to use the new interface.

IOAT driver: registration with DMA manager and polling of channels. Handling of requests.

IOAT DMA Driver: Removed the device handling functionality and replaced it with the library implementation

The domain is now only responsibel for initializing the library and
discovering the devices. Further depending on the library configuration,
the domain acts as a IOAT DMA device manager or as a request handler.