Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Create a generic way to support multiple boards within an
arm platform. Add all the atmel boards to the ATMEL kernel for
testing purposes. Until boot loader arg parsing of baord type
is done, this won't actually be able to do the runtime selection.

Initital support for AT91SAM9X25 SoC and the SAM9X25-EK evaluation
board. Much work remains.