soc: mediatek: knows_txdone needs to be set in Mediatek CMDQ helper

Mediatek CMDQ driver have a mechanism to do TXDONE_BY_ACK,
so we should set knows_txdone.

Fixes:576f1b4bc802 ("soc: mediatek: Add Mediatek CMDQ helper")

Cc: [e-mail] # v5.0+
Signed-off-by: Bibby Hsieh <[e-mail]>
Reviewed-by: CK Hu <[e-mail]>
Signed-off-by: Matthias Brugger <[e-mail]>

drivers/soc/mediatek/mtk-cmdq-helper.c

···
 	client->pkt_cnt = 0;
 	client->client.dev = dev;
 	client->client.tx_block = false;
+	client->client.knows_txdone = true;
 	client->chan = mbox_request_channel(&client->client, index);
 
 	if (IS_ERR(client->chan)) {