- 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 265440, 265441, 265444, 265445, 265446, 265447:

Move the pl310.enabled tunable to hw.pl310.enabled. Clean up a few minor
style(9) nits. Use DEVMETHOD_END.

Break out the code that figures out the L2 cache geometry to its own
routine, so that it can be called from multiple places in upcoming changes.

Call platform_pl310_init() before enabling the controller, and handle the
case where the controller is already enabled.

Add defines for the bits in the PL310 debug control register.

Add a public routine to set the L2 cache ram latencies. This can be
called by platform init routines to fine-tune cache performance.

Enable PL310 power-saving modes and tune the cache ram latencies for imx6.

MFC 265035: Move duplicated code to print l2 config into the common code.

MFC r257483, r257486, r257489:

Add the Soc- / machine-dependent parts of imx6 support.
Add dts source for imx6 SoCs and for Wandboard boards.
Add kernel config for Wandboard.

Add the Soc- / machine-dependent parts of imx6 support.