DISCO_H747I_CM4 compilation issue

SCB_DisableDCache() function is only available for M7 core.

Author: jeromecoutant

features/netsocket/emac-drivers/TARGET_STM/TARGET_STM32H7/TARGET_DISCO_H747I/stm32h7_eth_init.c

@@ -64,8 +64,10 @@ void HAL_ETH_MspInit(ETH_HandleTypeDef *heth)
 {
     GPIO_InitTypeDef GPIO_InitStruct;
     if (heth->Instance == ETH) {
+#if defined(CORE_CM7)
         /* Disable DCache for STM32H7 family */
         SCB_DisableDCache();
+#endif
 
         /* GPIO Ports Clock Enable */
         __HAL_RCC_GPIOA_CLK_ENABLE();