ARM: edma: Clean up and simplify the code around irq request

Get the two interrupt line number at the same time by merging the two
instance of if(node){}else{} places.
replace the &pdev->dev with the already existing dev which makes it possible
to collapse lines with devm_request_irq()

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>