- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

trim trailing spaces that have accumulated over the years (these files
served as the basis for too many other platforms).

Use BUS_DMA_COHERENT.

- Better use of the busdma API.
- Use spin locks instead of sleep locks.

Import dummy drivers for the i80321 DMA controller and AAU.
The DMA controller driver only knows how to do memory to memory copies, and
the AAU driver how to zero a chunk of memory.
Use them to process big (>=1KB) copying/zeroing.