dmaengine: remove iop-adma driver

The iop32x platform was removed, so this driver is no longer
needed.

Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/20221019150410.3851944-10-arnd@kernel.org


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