STM32 MDMA can be triggered by STM32 DMA channels transfer complete.

In case of non-null struct dma_slave_config .peripheral_size, it means the
DMA client wants the DMA to trigger the MDMA.

stm32-mdma driver gets the request id, the mask_addr, and the mask_data in
struct stm32_mdma_dma_config passed by DMA with struct dma_slave_config
.peripheral_config/.peripheral_size.

Then, as DMA is configured in Double-Buffer mode, and MDMA channel will
transfer data from/to SRAM to/from DDR, then bursts are optimized.
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20220829154646.29867-7-amelie.delaunay@foss.st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>