This adds support for populating derived properties of the mpc85xx SOC
which are not typically included in the dtb directly.
This update is based on U-Boot code from common/fdt_support.c
and arch/powerpc/cpu/mpc85xx/fdt.c - version git-2b26201.
Signed-off-by: Renaud Barbier <renaud.barbier@ge.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>