Bluetooth: btrtl: Load FW v2 otherwise FW v1 for RTL8852C

In this commit, prefer to load FW v2 if available. Fallback to FW v1
otherwise. This behavior is only for RTL8852C.

Fixes: 9a24ce5e

 ("Bluetooth: btrtl: Firmware format v2 support")
Cc: stable@vger.kernel.org
Suggested-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Tested-by: Hilda Wu <hildawu@realtek.com>
Signed-off-by: Max Chou <max.chou@realtek.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>