dmaengine: fsl-edma: explicitly freeup irq

dmaengine device should explicitly call devm_free_irq() when using
devm_request_irq().

The irq is still ON when devices remove is executed and irq should be
quiesced before remove is completed.

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Cc: Jingchang Lu <b35083@freescale.com>
Cc: Peter Griffin <peter.griffin@linaro.org>