clocksource/drivers/arm_global_timer: Remove stray tab

Remove a stray tab in global_timer_of_register() which is different from
the coding style in the rest of the driver.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20240218174138.1942418-3-martin.blumenstingl@googlemail.com