dmaengine: zynqmp_dma: Move list_del inside zynqmp_dma_free_descriptor.

List elements are not formally removed from list during zynqmp_dma_reset.

Signed-off-by: Rafal Hibner <rafal.hibner@secom.com.pl>
Link: https://lore.kernel.org/r/20200506102844.2259-1-rafal.hibner@secom.com.pl


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