dmaengine: xilinx_dma: Use tasklet_hi_schedule for timing critical usecase

Schedule tasklet with high priority to ensure that callback processing
is prioritized. It improves throughput for netdev dma clients.

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Link: https://lore.kernel.org/r/1691387509-2113129-7-git-send-email-radhey.shyam.pandey@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>