MIPS: FDT size is a be32

The totalsize field was be32. And the reserve bootmem would cause failure.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
To: devicetree-discuss@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: grant.likely@secretlab.ca
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Dezhong Diao <dediao@cisco.com>
Patchwork: https://patchwork.linux-mips.org/patch/1838/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>