dmaengine: stm32-dma: fix stm32_dma_get_max_width

buf_addr parameter of stm32_dma_set_xfer_param function is a dma_addr_t.
We only need to check the remainder of buf_addr/max_width, so, no need to
use do_div and extra u64 addr. Use '%' instead.

Fixes: e0ebdbdc ("dmaengine: stm32-dma: take address into account when computing max width")
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20211011094259.315023-3-amelie.delaunay@foss.st.com


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