ARM: vexpress: TC2 use sp804 timer as sched_clock

Use SP804 timer as sched_clock instead of arch timers as work-around
until the arch timers have been fixed.

Inspired by patch from Morten Rasmussen <Morten.Rasmussen@arm.com>
with the same description but made configurable by a device tree hack,
to enable a single kernel binary to be used with multiple CoreTiles.

Signed-off-by: Jon Medhurst <tixy@linaro.org>
3 files changed