stm32/boards/NUCLEO_H743ZI: Use priority 0 for SysTick IRQ.

This follows how all other boards are configured.

ports/stm32/boards/NUCLEO_H743ZI/stm32h7xx_hal_conf.h

@@ -166,7 +166,7 @@
   * @brief This is the HAL system configuration section
   */
 #define  VDD_VALUE                    ((uint32_t)3300) /*!< Value of VDD in mv */
-#define  TICK_INT_PRIORITY            ((uint32_t)0x0F) /*!< tick interrupt priority */
+#define  TICK_INT_PRIORITY            ((uint32_t)0x00) /*!< tick interrupt priority */
 #define  USE_RTOS                     0
 #define  USE_SD_TRANSCEIVER           0U               /*!< use uSD Transceiver */