powerpc/85xx: Rework P1010RDB and P1010 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
* Dropping "fsl,p1010-IP..." from compatibles for standard blocks
* PCI interrupt map - wrong IRQs for PCI-0 controller
* SDHC interrupt sense was wrong

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