dmaengine: dw: Enable iDMA 32-bit on Intel Elkhart Lake

Intel Elkhart Lake OSE (Offload Service Engine) provides few DMA controllers
to the host. Enable them in the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>