clocksource/drivers/timer-ti-dm: Get clock in probe with devm_clk_get()

We can simplify the code a bit by getting the clock in probe, and using
devm_clk_get(). This will also make further changes easier as the clock
is available in probe instead of prepare.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Link: https://lore.kernel.org/r/20220815131250.34603-10-tony@atomide.com


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