This dma_alloc_coherent() is undone in the remove function, but not in the
error handling path of fsl_qdma_probe().

Switch to the managed version to fix the issue in the probe and simplify
the remove function.

Fixes: b092529e ("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/a0ef5d0f5a47381617ef339df776ddc68ce48173.1704621515.git.christophe.jaillet@wanadoo.frSigned-off-by: Vinod Koul <vkoul@kernel.org>