Bluetooth: btqca: Add a short delay before downloading the NVM

On WCN3990 downloading the NVM sometimes fails with a "TLV response
size mismatch" error:

[  174.949955] Bluetooth: btqca.c:qca_download_firmware() hci0: QCA Downloading qca/crnv21.bin
[  174.958718] Bluetooth: btqca.c:qca_tlv_send_segment() hci0: QCA TLV response size mismatch

It seems the controller needs a short time after downloading the
firmware before it is ready for the NVM. A delay as short as 1 ms
seems sufficient, make it 10 ms just in case. No event is received
during the delay, hence we don't just silently drop an extra event.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btqca.c

@@ -388,6 +388,9 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
 		return err;
 	}
 
+	/* Give the controller some time to get ready to receive the NVM */
+	msleep(10);
+
 	/* Download NVM configuration */
 	config.type = TLV_TYPE_NVM;
 	if (firmware_name)