[POWERPC] QE: Add ability to upload QE firmware

Define the layout of a binary blob that contains a QE firmware and instructions
on how to upload it.  Add function qe_upload_firmware() to parse the blob
and perform the actual upload.  Fully define 'struct rsp' in immap_qe.h to
include the actual RISC Special Registers.  Added description of a new
QE firmware node to booting-without-of.txt.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>