Bootloaders can pass version 3 of this structure.  Add the new fields
so we can support the Device Tree.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2938/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>