x86, olpc: Add missing elements to device tree

In response to new device tree code in the kernel, OLPC will start
using it for probing of certain devices. However, some firmware fixes
are needed to put the devicetree into a usable state.

Retain compatibility with old firmware by fixing up the device tree
at boot-time if it does not contain the new nodes/properties that
we need for probing. This is the same approach taken on PPC platforms.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Link: http://lkml.kernel.org/r/1309019658-1712-2-git-send-email-dsd@laptop.org
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Andres Salomon <dilinger@queued.net>
Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>