[nrf fromlist] drivers: timer: grtc: Fix ticks calculation for GRTC

Fixed calculation of GRTC ticks inside
`z_nrf_grtc_timer_get_ticks()` function.

Upstream PR: zephyrproject-rtos/zephyr#71688

Signed-off-by: Adam Kondraciuk <adam.kondraciuk@nordicsemi.no>

Author: adamkondraciuk

drivers/timer/nrf_grtc_timer.c

@@ -319,18 +319,21 @@ uint64_t z_nrf_grtc_timer_get_ticks(k_timeout_t t)
 	int64_t curr_tick;
 	int64_t result;
 	int64_t abs_ticks;
+	int64_t grtc_ticks;
 
 	curr_time = counter();
 	curr_tick = sys_clock_tick_get();
 
+	grtc_ticks = t.ticks * CYC_PER_TICK;
 	abs_ticks = Z_TICK_ABS(t.ticks);
 	if (abs_ticks < 0) {
 		/* relative timeout */
-		return (t.ticks > (int64_t)COUNTER_SPAN) ? -EINVAL : (curr_time + t.ticks);
+		return (grtc_ticks > (int64_t)COUNTER_SPAN) ?
+			-EINVAL : (curr_time + grtc_ticks);
 	}
 
 	/* absolute timeout */
-	result = abs_ticks - curr_tick;
+	result = (abs_ticks - curr_tick) * CYC_PER_TICK;
 
 	if (result > (int64_t)COUNTER_SPAN) {
 		return -EINVAL;

include/zephyr/drivers/timer/nrf_grtc_timer.h

@@ -111,7 +111,7 @@ uint64_t z_nrf_grtc_timer_compare_read(int32_t chan);
  *
  * @param chan Channel ID.
  *
- * @param target_time Absolute target time in ticks.
+ * @param target_time Absolute target time in GRTC ticks.
  *
  * @param handler User function called in the context of the GRTC interrupt.
  *