ARM: DT: binding fixup to align with vendor-prefixes.txt

[ this is a follow-up to this discussion:
http://archive.arm.linux.org.uk/lurker/message/20130730.230827.a1ceb12a.en.html ]
This patchset renames all uses of "bcm," name bindings to
"brcm," as they were done prior to knowing that brcm had
already been standardized as Broadcom vendor prefix
(in Documentation/devicetree/bindings/vendor-prefixes.txt).
This will not cause any churn on devices because none of
these bindings have made it into production yet.
Also rename the the following dt binding docs that had "bcm,"
in their name for consistency:
 - bcm,kona-sdhci.txt -> kona-sdhci.txt
 - bcm,kona-timer.txt -> kona-timer.txt

Acked-by: Stephen Warren <swarren@nvidia.com>