AP MLD: Set WLAN_STA_ASSOC flag before copying STA entry (SME-in-driver)

AP MLD: Set WLAN_STA_ASSOC flag before copying STA entry (SME-in-driver)

In SME offloaded cases, it was found that WLAN_STA_ASSOC flag is
not set on all STA entries. This is because STA entries are
copied before WLAN_STA_ASSOC flag is set in the assocation link.

To fix that, set WLAN_STA_ASSOC flag properly before calling
hostapd_process_assoc_ml_info() where flags are copied to STA
entries in other links.

Signed-off-by: Chenming Huang <quic_chenhuan@quicinc.com>