Bluetooth: hci_qca: Retry btsoc initialize when it fails

This patch adds the retry of btsoc initialization when it fails. There are
reports that the btsoc initialization may fail on some platforms but the
repro ratio is very low. The symptoms is the firmware downloading failed
due to the UART write timed out. The failure may be caused by UART,
platform HW or the btsoc itself but it's very difficlut to root cause,
given the repro ratio is very low. Add a retry for the btsoc initialization
can work around most of the failures and make Bluetooth finally works.

Signed-off-by: Rocky Liao <rjliao@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>