imxrt10xx: fix LED blinking

The LED write routine is meant to take a value between 0 for off and 255 for full brightness.
the current 10xx port treats 0 as off, and anything else as on.  This creates a case where the
LED is on virtually all the time, except for a tiny blink off every 256 timer intervals.

(this is for non-pwm, simple LEDs)

This fix makes (value >= 128) is ON and (value < 128) off, and the LED looks right.

Author: ccrome

ports/mimxrt10xx/boards.c

@@ -262,8 +262,6 @@ void SysTick_Handler(void)
 
 void board_led_write(uint32_t value)
 {
-  (void) value;
-
 #ifdef LED_PINMUX
 #ifdef LED_PWM_PINMUX
   if (_dfu_mode)
@@ -274,6 +272,7 @@ void board_led_write(uint32_t value)
   }else
 #endif
   {
+    value = (value >= 128) ? 1 : 0;
     GPIO_PinWrite(LED_PORT, LED_PIN, value ? LED_STATE_ON : (1-LED_STATE_ON));
   }
 #endif