- 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 r273257:
Add a driver for the TI watchdog.

The TI watchdog timer is present on BeagleBone's. Since 2014, U-Boot
has been booting the BeagleBone with the watchdog enabled. We need
to
disable it on boot to avoid a spurious reset.
The timer isn't exactly precise, but it will do as a watchdog. This
is also a reflection of the watchdog(9) API.

In the future, we could handle interrupts, but the watchdog(9) API
needs to be a bit smarter before that can happen.

Add a driver for the TI watchdog.

The TI watchdog timer is present on BeagleBone's. Since 2014, U-Boot
has been booting the BeagleBone with the watchdog enabled. We need to
disable it on boot to avoid a spurious reset.
The timer isn't exactly precise, but it will do as a watchdog. This
is also a reflection of the watchdog(9) API.

In the future, we could handle interrupts, but the watchdog(9) API
needs to be a bit smarter before that can happen.

Differential Revision: https://reviews.freebsd.org/D965
Reviewed by: andrew
MFC after: 1 week
Relnotes: yes