- Copy stable/10@285827 to releng/10.2 in preparation for 10.2-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.2.
- Update default pkg(8) configuration to use the quarterly branch.[1]

Discussed with: re, portmgr [1]
Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC: r258427, r258694

r258694:
Make RTAS calls, which call setfault() to recover from machine checks,
preserve any existing fault buffer. RTAS calls are meant to be safe from
interrupt context (and are indeed used there to implement the xics PIC
driver). Without this, calling into RTAS in interrupt context would have
the effect of clearing any existing onfault state of the interrupted
thread, potentially leading to a panic.

r258427:
For PCI<->PCI bridges, #address-cells may be 3. Allow this when parsing the
ibm,dma-window properties. This is especially a concern when
#ibm,dma-address-cells is not specified and we have to use the regular
#address-cells property.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Use a spin lock instead of a mutex to gate RTAS. This is required if RTAS
calls are involved in interrupt handling.

Approved by: re (kib)

Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.

This means that their use is restricted to a single C file.

Add better error handling for RTAS calls. These can potentially cause
machine checks (e.g. invalid PCI configuration cycles), but these can
be caught and recovered from. This change also the RTAS PCI driver to
work without modification as a replacement for the Grackle driver on
Grackle-based Powermacs.

MFpseries:
Renovate and improve the AIM Open Firmware support:
- Add RTAS (Run-Time Abstraction Services) support, found on all IBM systems
and some Apple ones
- Improve support for 32-bit real mode Open Firmware systems
- Pull some more OF bits over from the AIM directory
- Fix memory detection on IBM LPARs and systems with more than one /memory
node (by andreast@)