boards: board_app_initialize() don't return early on failure

- depending on the situation we're more likely to get actionable user
feedback by allowing boot to complete rather than silently failing

boards/mro/ctrl-zero-h7/src/init.c

@@ -186,12 +186,10 @@ __EXPORT int board_app_initialize(uintptr_t arg)
 
 	if (!sdio_dev) {
 		syslog(LOG_ERR, "[boot] Failed to initialize SDIO slot %d\n", 0);
-		return ERROR;
 	}
 
 	if (mmcsd_slotinitialize(0, sdio_dev) != OK) {
 		syslog(LOG_ERR, "[boot] Failed to bind SDIO to the MMC/SD driver\n");
-		return ERROR;
 	}
 
 	/* Assume that the SD card is inserted.  What choice do we have? */