[][MAC80211][hostapd][Fix extender mode issues]

[Description]
Fix extender mode issues about BSS color and BSS load update.

1. MAC80211 re-assigns beacon during BSS color switch procedure, which is
unexpected when the BSS is currently stopped by wpa_supplicant.
Therefore, a condition added in hostapd_switch_color to prevent it.

2. Fix the issue that the Extender (AP + STA) AP interface does not update
BSS load after STA interface finishes connection.

[Release-log]
N/A

Change-Id: Idd97be8ad1baa8066d101030aa474e4891584151
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7753518
3 files changed