dmaengine: fsldma: Fix a resource leak in the remove function

A 'irq_dispose_mapping()' call is missing in the remove function.
Add it.

This is needed to undo the 'irq_of_parse_and_map() call from the probe
function and already part of the error handling path of the probe function.

It was added in the probe function only in commit d3f620b2 ("fsldma:
simplify IRQ probing and handling")

Fixes: 77cd62e8 ("fsldma: allow Freescale Elo DMA driver to be compiled as a module")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/20201212160516.92515-1-christophe.jaillet@wanadoo.frSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/fsldma.c

@@ -1314,6 +1314,7 @@ static int fsldma_of_remove(struct platform_device *op)
 		if (fdev->chan[i])
 			fsl_dma_chan_remove(fdev->chan[i]);
 	}
+	irq_dispose_mapping(fdev->irq);
 
 	iounmap(fdev->regs);
 	kfree(fdev);