This reverts commit f91b1e73.

As explained by Lars-Peter Clausen:

"This creates a resource leak. dmaengine_pcm_request_chan_of() requests
bothtransmit and receive channels. It might return with an error if one
of them fails, but the other one succeeded. In this case we need to call
dmaengine_pcm_release_chan() to free the requested channel"

So revert the commit.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>