[AVR32] Fix incorrect invalidation of shared cachelines
Fix bug in dma_map_single(..., DMA_FROM_DEVICE) caused by incorrect
invalidation of shared cachelines at the beginning and/or end of
the specified buffer. Those shared cachelines need to be flushed,
since they may hold valid data (which must not be discarded).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>