dmaengine: mxs-dma: Remove the unused .id_table

The mxs-dma driver is only used by DT platforms and the .id_table
is unused.

Get rid of it to simplify the code.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20201123193051.17285-1-festevam@gmail.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>