Bluetooth: btqca: Reset download type to default

This patch will reset the download flag to default value
before retrieving the download mode type.

Fixes: 32646db8

 ("Bluetooth: btqca: inject command complete event during fw download")
Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
Tested-by: Claire Chang <tientzu@chromium.org>
Reviewed-by: Claire Chang <tientzu@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>