renesas-ra/ra: Fix SysTick clock source.

The SysTick_Config function must use the system/CPU clock to configure the
ticks.

Signed-off-by: iabdalkader <i.abdalkader@gmail.com>

ports/renesas-ra/ra/ra_config.h

@@ -26,6 +26,7 @@
 #define RA_RA_CONFIG_H_
 
 #include <stdint.h>
+#include "py/mpconfig.h"
 
 #if defined(RA4M1) | defined(RA4W1)
 #define SCI_CH_MAX      10

ports/renesas-ra/ra/ra_init.c

@@ -30,7 +30,7 @@
 
 void ra_init(void) {
     ra_int_init();
-    SysTick_Config(PCLK / 1000);
+    SysTick_Config(MICROPY_HW_MCU_SYSCLK / 1000);
     internal_flash_init();
 }