clocksource/drivers/timer-atmel-tcb: Convert tc_clksrc_suspend|resume() to static

Statisticize tc_clksrc_suspend and tc_clksrc_resume.

Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>