dmaengine: fsl-qdma: Fix a memory leak related to the queue command DMA

dmaengine: fsl-qdma: Fix a memory leak related to the queue command DMA

This dma_alloc_coherent() is undone neither in the remove function, nor in
the error handling path of fsl_qdma_probe().

Switch to the managed version to fix both issues.

Fixes: b092529e0aa0 ("dmaengine: fsl-qdma: Add qDMA controller driver for Layerscape SoCs")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/7f66aa14f59d32b13672dde28602b47deb294e1f.1704621515.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul <vkoul@kernel.org>