MIMXRT1050: Update the usticker driver

The PIT module should be initialized only once

Signed-off-by: Mahesh Mahadevan <mahesh.mahadevan@nxp.com>

Author: mmahadevan108

targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_IMX/us_ticker.c

@@ -50,18 +50,18 @@ void us_ticker_init(void)
 {
     /* Common for ticker/timer. */
     uint32_t busClock;
-    /* Structure to initialize PIT. */
-    pit_config_t pitConfig;
 
     us_ticker_setup_clock();
 
-    PIT_GetDefaultConfig(&pitConfig);
-    PIT_Init(PIT, &pitConfig);
-
     busClock = us_ticker_get_clock();
 
     /* Let the timer to count if re-init. */
     if (!us_ticker_inited) {
+        /* Structure to initialize PIT. */
+        pit_config_t pitConfig;
+
+        PIT_GetDefaultConfig(&pitConfig);
+        PIT_Init(PIT, &pitConfig);
 
         PIT_SetTimerPeriod(PIT, kPIT_Chnl_0, busClock / 1000000 - 1);
         PIT_SetTimerPeriod(PIT, kPIT_Chnl_1, 0xFFFFFFFF);