[netbsd-10] src bus_dma.9 copyedit

[Van Ly]

Hello,

The final sentence in the block for BUS_DMA_NOCACHE and
BUS_DMA_PREFECTCHABLE need to be swapped, see pink and yellow
highlight below

=> http://sdf.org/~van.ly/art/bus-dma-9-copyedit.jpeg

-- 
vl