- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

MFC r282516:

Add the code necessary to run the imx6 chip at its lowest clock/power
operating point (396MHz/950mV).

MFC r268838, r277644:

Add support for Toradex Apalis i.MX6 development board.

Add support for imx6 audio transmitting, include drivers for:
o Digital Audio Multiplexer (AUDMUX)
o Smart Direct Memory Access Controller (SDMA)
o Synchronous Serial Interface (SSI)

MFC r269607, r269698:

Cache the imx6 SoC type in a static var so that it only has to be figured
out by sniffing hardware registers once.

Add a missing clock register definition.

MFC r262534, r262548, r262549, r262552, r262568, r262581, r262583, r262584,
r262585, r262587, r262696, r262712

Replace many pasted identical definitions of cpu_initclocks() with a common
implementation in arm/machdep.c.

aicasm: Don't complain about missing prototypes to ease bootstrap issues.

Vybrid: Add driver for Inter-Integrated Circuit (I2C).

imx6: Initialize the Low Power Mode bits to keep the ARM cores running
during WFI.

All our current ARM multi-core systems have all cores in one package with
a shared L2 cache, reflect that in the common cpu_topo() routine.

mpcore timer: Supply a DELAY() implementation via weak linkage, so that
SoC-specific code can supply a better implementation.

imx6: Add some rudimentary voltage control.

Add an armv7 implementation of cpu_sleep().

Add __used attribute so that the DELAY implementation doesn't get
optimized away as unreferenced, causing linker errors when trying to
resolve the weak reference to the missing function.

MFC r257453: Add stubbed-out imx6 support for clocks and power management.

Add stubbed-out imx6 support for clocks and power management. This
contains little more than a few stub functions required to keep the
linker happy, but it's enough to let early imx6 development proceed.