dmaengine: xilinx_dma: use readl_poll_timeout_atomic variant

dmaengine: xilinx_dma: use readl_poll_timeout_atomic variant

The xilinx_dma_poll_timeout macro is sometimes called while holding a
spinlock (see xilinx_dma_issue_pending() for an example) this means we
shouldn't sleep when polling the dma channel registers. To address it
in xilinx poll timeout macro use readl_poll_timeout_atomic instead of
readl_poll_timeout variant.

Signed-off-by: Marc Ferland <ferlandm@amotus.ca>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Link: https://lore.kernel.org/r/1604473206-32573-2-git-send-email-radhey.shyam.pandey@xilinx.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>