Fix processing of channel list update events

Fix processing of channel list update events

Commit 6bf731e8cea4d9d41665d271b331e096c7c569e9 broke handling of
EVENT_CHANNEL_LIST_CHANGED by introducing a cached copy of the driver
channel list that does not get updated even if driver changes its list.
Fix this by synchronizing the cacched wpa_s->hw.modes information
whenever EVENT_CHANNEL_LIST_CHANGED is processed. This fixes P2P channel
list updates based on regulatory domain hints that may trigger driver to
change its supported channel list.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
intended-for: hostap-1