hide DMA2D in kernel

[TychoVrahe]

Followup for #4188

Direct DMA2D usage might be too powerful.

Lets consider hiding the implementation behind syscalls, where we can validate parameters and control, what gets copied where.

Downside would be that this adds some overhead to the calls, so it might impact graphical performance. This should be therefore benchmarked and if the impact is too high, lets optimize the DMA2D usage, perhaps with direct peripheral/registers usage without STM32 HAL.