kernel: timer: Fix incorrect behavior for timers with K_FOREVER period

Zephyr docs state that timers will act as one-shot timers when started
with a period of K_NO_WAIT or K_FOREVER. However the code adjusting
period was setting K_FOREVER timeout ticks to 1 which caused the timer
to expire every tick. This adds a check to not adjust K_FOREVER periods

Signed-off-by: Eric Johnson <eric@liveathos.com>

kernel/timer.c

@@ -126,7 +126,8 @@ void z_impl_k_timer_start(struct k_timer *timer, k_timeout_t duration,
 	 * argument the same way k_sleep() does), but historical.  The
 	 * timer_api test relies on this behavior.
 	 */
-	if (period.ticks != 0 && Z_TICK_ABS(period.ticks) < 0) {
+	if (!K_TIMEOUT_EQ(period, K_FOREVER) && period.ticks != 0 &&
+	    Z_TICK_ABS(period.ticks) < 0) {
 		period.ticks = MAX(period.ticks - 1, 1);
 	}
 	if (Z_TICK_ABS(duration.ticks) < 0) {