fix the non-coherent coldfire dma_alloc_coherent

Christoph Hellwig
2023-10-09T07:41:42Z

Hi all,

this is the next attempt to not return memory that is not DMA coherent
on coldfire/m68knommu. The last one needed more fixups in the fec
driver, which this versions includes. On top of that I've also added
a few more cleanups to the core dma allocation code.

Jim: any work to support the set_uncached and remap method for arm32
should probably be based on this, and patch 3 should make that
selection a little easier.