dmaengine: mic_x100_dma: use devm_kzalloc to fix an issue

The following patch introduced an issue.
    commit f6206f00 ("dmaengine: mic_x100_dma: use the new helper to simplify the code")

This issue is :

	kfree(mic_dma_dev)
	.....
	dma_async_device_unregister(mic_dma_dev->device);

Free the memory, and use it again.

So use devm_kzalloc to allocate mic_dma_dev to fix it.

When the Devres try to release the resources, it will call release at the
following order:

	dma_async_device_unregister(mic_dma_dev->device);
	.....
	kfree(mic_dma_dev)

Fixes: f6206f00 ("dmaengine: mic_x100_dma: use the new helper to simplify the code")
Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai>
Signed-off-by: Vinod Koul <vkoul@kernel.org>