dmaengine: Revert "dmaengine: fsl-edma: add i.mx7ulp edma2 version support"

This reverts commit 7144afd0

 ("dmaengine: fsl-edma: add i.mx7ulp
edma2 version support") as this fails to build with module option due to
usage of of_irq_count() which is not an exported symbol as kernel
drivers are *not* expected to use it (rightly so).

Signed-off-by: Vinod Koul <vkoul@kernel.org>