clocksource/drivers/sun4i-timer: Only register a sched_clock on sun4i and sun5i

sun6i and newer have an arm arch timer which is a better
sched_clock source then the sun4i-timer, and sched_clock does
not have priorities, so do not register the sun4i-timer
sched_clock at all on sun6i and newer.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: ben.dooks@codethink.co.uk
Cc: digetx@gmail.com
Cc: laurent.pinchart+renesas@ideasonboard.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: viresh.kumar@linaro.org
Link: http://lkml.kernel.org/r/1427746633-9137-8-git-send-email-daniel.lezcano@linaro.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>