Bluetooth: Mesh: Fixes Unable recovery twice even after 192h

After PR: https://github.com/zephyrproject-rtos/zephyr/pull/38296



If we receive the second recovery after 192 hours after the first
recovery, we may still not be able to perform any recovery, even
if the IV Index differs by 42, because the `ivi_was_recovered` flag
will only be cleared during the iv update.

But still May lose iv update, as we did the first iv recovery.

This patch by checking the iv duration, if 192h later, auto clear
`ivi_was_recovered` flag.

Signed-off-by: Lingao Meng <menglingao@xiaomi.com>