Revert "mwifiex: advertise PS ON by default support to cfg80211"

This reverts upstream commit c2b6680f63f which enables driver to enter
powersave as soon as connected.

Reason: Causes firmware hang with message "Firmware wakeup failed",
and also bluetooth becomes inaccessible.

See b/28425386

Change-Id: If704a863f9f01a38bdff6325cd4faa27524ac55f
1 file changed