powerpc/dma: remove set_dma_offset

There is no good reason for this helper, just opencode it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
8 files changed