Bluetooth: hci_qca: Reduce delay after sending baudrate request for WCN3990

The current 300ms delay after a baudrate change is extremely long.
For WCN3990 it is sufficient to wait 10ms after the baudrate change
request has been sent over the wire.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>