IDC: fix message cache handling

When an IDC message is received from another core, the receiver core
doesn't have any useful data for it in cache. Writing back the cache
can corrupt the message data. Cache has to be invalidated instead.

Signed-off-by: Guennadi Liakhovetski <[email protected]>

src/idc/zephyr_idc.c

@@ -63,7 +63,7 @@ static void idc_handler(struct k_p4wq_work *work)
 	int payload = -1;
 	k_spinlock_key_t key;
 
-	sys_cache_data_flush_range(msg, sizeof(*msg));
+	sys_cache_data_invd_range(msg, sizeof(*msg));
 
 	if (msg->size == sizeof(int)) {
 		const int idc_handler_memcpy_err __unused =