dmaengine: imx-sdma: Set DMA channel to be private

If async-tx is loaded before device drivers that requires imx-sdma, the
dmaengine_get() routine from async-tx grabs all non-private channels,
so devices that require DMA fail to work.

So mark imx-sdma with DMA_PRIVATE to avoid such situation.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20230207045745.1029959-1-kai.heng.feng@canonical.com


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