Use user data to replace DMA's device pointer in
the callback function so that the user can retrieve
its context by that private data.
Signed-off-by: Jun Li <jun.r.li@intel.com>
Add dma driver for Nios-II Modular Scatter-Gather DMA soft IP.
This driver relies upon the Altera HAL msgdma driver for all
the dma core register programming and interrupt handling.
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>