OWE: Skip beacon update of transition BSS if it is not yet enabled

OWE: Skip beacon update of transition BSS if it is not yet enabled

When a single hostapd process manages both the OWE and open BSS for
transition mode, owe_transition_ifname can be used to clone the
transition mode information (i.e., BSSID/SSID) automatically. When both
BSSs use ACS, the completion of ACS on the 1st BSS sets state to
HAPD_IFACE_ENABLED and the OWE transition mode information is updated
for all the other BSSs. However, the 2nd BSS is still in the ACS phase
and the beacon update messes up the state for AP startup and prevents
proper ACS competion.

If 2nd BSS is not yet enabled (e.g., in ACS), skip beacon update and
defer OWE transition information cloning until the BSS is enabled.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>