dmaengine: imx-sdma: Move message level to debug

Since commit d078cd1b ("dmaengine: imx-sdma: Add imx6sx platform
support") we get this message on every boot on mx6q:

imx-sdma 20ec000.sdma: no event needs to be remapped

, which is not very helpful.

Move the message to debug level instead.

Cc: Zidan Wang <zidan.wang@freescale.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>