This patch adds clocksource support for ARMv7-M's System timer,
also known as SysTick.
Tested-by: NChanwoo Choi <cw00.choi@samsung.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NMaxime Coquelin <mcoquelin.stm32@gmail.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>