powerpc/e500v2: Add Power ISA properties to comply with ePAPR 1.1

power-isa-version and power-isa-* are cpu node general properties defined
in ePAPR.

If the power-isa-version property exists, then for each category from the
Categories section of Book I of the Power ISA version indicated, the
existence of a property named power-isa-[CAT], where [CAT] is the
abbreviated category name with all uppercase letters converted to
lowercase, indicates that the category is supported by the implementation.

The patch update all e500v2 platforms.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Olivia Yin <hong-hua.yin@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

powerpc/85xx: Rework MPC8568MDS device tree

Utilize new split between board & SoC, and new SoC device trees split
into pre & post utilizing 'template' includes for SoC IP blocks.

Other changes include:
* Moved to a standard 2 #address-cells & #size-cells at top-level
* Moved to specifying interrupt-parent for mpic at root
* Moved to 4-cell mpic interrupt cells to support MPIC timers
* Removed CPU properties setup by u-boot to match other .dts
* Reworked PCIe nodes to allow supportin IRQs for controller (errors)
and moved PCI device IRQs down to virtual bridge level
* Dropping "fsl,mpc8568-IP..." from compatibles for standard blocks

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>