device tree,arm: supply a flat device tree to dom0

device tree,arm: supply a flat device tree to dom0

Build a flat device tree for dom0 based on the one supplied to Xen.
The following changes are made:

  * In the /chosen node, the xen,dom0-bootargs parameter is renamed to
    bootargs.

  * In all memory nodes, the reg parameters are adjusted to reflect
    the amount of memory dom0 can use.  The p2m is updated using this
    info.

Support for passing ATAGS to dom0 is removed.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
[ removed device_tree_dump call -- ijc ]
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>