[refactor] remove parallel dma request

Remove from dma-linux-par the ability to create a single request using
multiple threads.

This is will be fixed once we get the new tilings inside master, but in
the meantime it is too complex to generalize splitting a layout among
multiple threads.
5 jobs for new-dma-design in 30 minutes and 21 seconds (queued for 1 second)
Status Job ID Name Coverage
  Style
passed #44161
integration
checkpatch

00:00:39

passed #44160
integration
repoquality

00:05:35

 
  Build
passed #44162
make:generic

00:08:51

passed #44164
knl
make:knl

00:07:05

passed #44163
make:out-of-tree

00:08:49