dmaengine: zynqmp_dma: fix lockdep warning in tasklet

dmaengine: zynqmp_dma: fix lockdep warning in tasklet

The tasklet that handles the completed dma transfers uses spin_unlock
for unlocking a spin lock that was previously locked with
spin_lock_irqsave.

This caused the following lockdep warning about an inconsistent lock
state:

	inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.

We must use spin_lock_irqsave, because it is possible to queue DMA
transfers from an irq handler.

Replace the spin_unlock and spin_lock by spin_unlock_irqrestore and
spin_lock_irqsave.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Link: https://lore.kernel.org/r/20210826094742.1302009-8-m.tretter@pengutronix.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>