When driver is coming up, mac80211 will set changed as ~0 (0xffffffff),
and driver could enter IDLE state (power off) before switching channel or
other config event. So move rtw_enter_ips() to the last, to make sure the
driver completed the config events before going to IDLE state.

So, moves leave/enter IPS config to be first/last one according to flag
IEEE80211_CONF_IDLE. If there're more configureations we want to add in
the future, they must locate between leave/enter IPS.
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Reviewed-by: Chris Chiu <chiu@endlessm.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>