powerpc/512x: add a device tree binding for LocalPlus Bus FIFO

Add a device tree binding for Freescale MPC512x LocalPlus Bus FIFO and
introduce the document describing that binding.

Signed-off-by: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
3 files changed