app/test: store digest/IV at a DMA able address

app/test: store digest/IV at a DMA able address

For physical crypto devices, IV and digest are processed by the crypto
device which needs the contents to be written on some DMA able address.

So in order to do that, IV and digest are accomodated in the packet.

Signed-off-by: Akhil Goyal <akhil.goyal@nxp.com>
Acked-by: Fiona Trahe <fiona.trahe@intel.com>