drivers: timer : fix rtmr timer.

RTMR clear the interrupt status bit in the init and isr function.

Signed-off-by: Lin Yu-Cheng <lin_yu_cheng@realtek.com>

Author: JasonLin-RealTek

drivers/timer/realtek_rts5912_rtmr.c

@@ -43,9 +43,9 @@ BUILD_ASSERT(DT_NUM_INST_STATUS_OKAY(DT_DRV_COMPAT) == 1,
 #define RTMR_ADJUST_CYCLES 7
 
 static struct k_spinlock lock;
-static uint32_t accumulated_cycles;
-static uint32_t previous_cnt;      /* Record the counter set into RTMR */
-static uint32_t last_announcement; /* Record the last tick announced to system */
+static uint32_t accumulated_cycles = 0;
+static uint32_t previous_cnt = 0;      /* Record the counter set into RTMR */
+static uint32_t last_announcement = 0; /* Record the last tick announced to system */
 
 static void rtmr_restart(uint32_t counter)
 {
@@ -74,6 +74,8 @@ static void rtmr_isr(const void *arg)
 
 	k_spinlock_key_t key = k_spin_lock(&lock);
 
+	RTMR_REG->INTSTS = 1ul;
+
 	rtmr_restart(RTMR_COUNTER_MAX * CYCLES_PER_TICK);
 
 	cycles = previous_cnt;
@@ -220,6 +222,8 @@ void arch_busy_wait(uint32_t n_usec)
 static int sys_clock_driver_init(void)
 {
 	/* Enable RTMR clock power */
+	RTMR_REG->INTSTS = 1ul;
+	NVIC_ClearPendingIRQ(DT_INST_IRQN(0));
 
 	SYSTEM_Type *sys_reg = RTS5912_SCCON_REG_BASE;