- 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 r279723, r279724:

Define new linker set, UART_FDT_CLASS_AND_DEVICE, for registering full
(class and device) FDT UART. Define second one, UART_FDT_CLASS, for UART
class only.

Move the uart_class definitions and fdt compat data into the individual
uart implementations, and export them using the new linker-set mechanism.

MFC r277132: Rename Exynos UART driver functions. No functional change.

MFC r266942, r266944:

Do only receive chars if there are some data in the buffer.
This fixes operation on newer Exynos boards.

Rename exynos uart driver filenames.

Rename exynos uart driver filenames.

Do only receive chars if there are some data in the buffer.
This fixes operation on newer Exynos boards.

Import basic support for Samsung Exynos 5 support.

Submitted by: Ruslan Bukin <br@bsdpad.com>
Reviewed by: gonzo