dmaengine: xilinx_dma: Clear desc_pendingcount in xilinx_dma_reset

[ Upstream commit 8a631a5a

 ]

Whenever we reset the channel, we need to clear desc_pendingcount
along with desc_submitcount. Otherwise when a new transaction is
submitted, the irq coalesce level could be programmed to an incorrect
value in the axidma case.

This behavior can be observed when terminating pending transactions
with xilinx_dma_terminate_all() and then submitting new transactions
without releasing and requesting the channel.

Signed-off-by: Nicholas Graumann <nick.graumann@gmail.com>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Link: https://lore.kernel.org/r/1571150904-3988-8-git-send-email-radhey.shyam.pandey@xilinx.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>