ALSA: hrtimer: Avoid direct access to hrtimer clockbase

The field timer->base->get_time is a private implementation detail and
should not be accessed outside of the hrtimer core.

Switch to the equivalent helper.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/all/20250821-hrtimer-cleanup-get_time-v2-5-3ae822e5bfbd@linutronix.de

Author: t-8ch

sound/core/hrtimer.c

@@ -44,7 +44,7 @@ static enum hrtimer_restart snd_hrtimer_callback(struct hrtimer *hrt)
 	}
 
 	/* calculate the drift */
-	delta = ktime_sub(hrt->base->get_time(), hrtimer_get_expires(hrt));
+	delta = ktime_sub(hrtimer_cb_get_time(hrt), hrtimer_get_expires(hrt));
 	if (delta > 0)
 		ticks += ktime_divns(delta, ticks * resolution);