convert to Unix line endings
fix rst style
improve DMA mapping

do not rely on old usb functions, but directly use dma_map_sq...
and skip it completely, by relying on the USB core to do it.

Some success to use it, when the kernel was just booted, after it keeps having
problems with "nommu_map_sg: overflow 10c933000+4096 of device mask ffffffff"
some whitespace cleanup