clocksource/drivers/timer-ti-dm: Drop unused functions

We still have some unused functions left, let's drop them.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Link: https://lore.kernel.org/r/20220815131250.34603-2-tony@atomide.com


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>