clocksource/drivers/timer-ti-dm: Make timer_get_irq static

We can make timer_get_irq() static as noted by Janusz. It is only used by
omap_rproc_get_timer_irq() via platform data.

Reported-by: Janusz Krzysztofik <[e-mail]>
Signed-off-by: Tony Lindgren <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Daniel Lezcano <[e-mail]>

drivers/clocksource/timer-ti-dm.c

···
 	return 0;
 }
 
-int omap_dm_timer_get_irq(struct omap_dm_timer *cookie)
+static int omap_dm_timer_get_irq(struct omap_dm_timer *cookie)
 {
 	struct dmtimer *timer = to_dmtimer(cookie);
 	if (timer)

include/clocksource/timer-ti-dm.h

···
 struct omap_dm_timer {
 };
 
-int omap_dm_timer_get_irq(struct omap_dm_timer *timer);
-
 u32 omap_dm_timer_modify_idlect_mask(u32 inputmask);
 
 /*