dmaengine: xilinx: xdma: Clarify kdoc in XDMA driver

dmaengine: xilinx: xdma: Clarify kdoc in XDMA driver

[ Upstream commit 7a71c6dc21d5ae83ab27c39a67845d6d23ac271f ]

Clarify the kernel doc of xdma_fill_descs(), especially how big chunks
will be handled.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
Link: https://lore.kernel.org/stable/20240327-digigram-xdma-fixes-v1-3-45f4a52c0283%40bootlin.com
Link: https://lore.kernel.org/r/20240327-digigram-xdma-fixes-v1-3-45f4a52c0283@bootlin.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>