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 P2020DS 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 specifying interrupt-parent for mpic at root
* Moved to 4-cell mpic interrupt cells to support MPIC timers
* Reworked PCIe nodes to allow supportin IRQs for controller (errors)
and moved PCI device IRQs down to virtual bridge level
* Updated spi node to new espi binding specification
* Renamed 'sdhci' node to 'sdhc'
* Changed GPIO compatiable from 'fsl,mpc8572-gpio' to 'fsl,pq3-gpio' as the
'mpc8572' compatiable is to deal with a 'mpc8572' specific to an erratum
* Fixed wrong reg offsets for mdio nodes associated with etsec2 & etsec3
* Dropping "fsl,p2020-IP..." from compatibles for standard blocks

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