clocksource/drivers/vf-pit: Consolidate calls to pit_*_disable/enable

clocksource/drivers/vf-pit: Consolidate calls to pit_*_disable/enable

The difference between the pit_clocksource_enable() and
pit_clocksource_disable() is only setting the TIF flag for the
clockevent. Let's group them and pass the TIF flag parameter to the
function so we save some lines of code. But as the base address is
different regarding if it is a clocksource or a clockevent, we pass
the base address in parameter instead of the struct pit_timer.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20250804152344.1109310-17-daniel.lezcano@linaro.org