wlan: Change check to see if peer device requires PMF

A change is made to the check that is done during
association to determine if the peer device requires
PMF (802.11w) connections.  Previously, the check
was to see if the peer required PMF.  Now the check
is to see if the peer device requires PMF and is also
PMF capable.

This change accommodates devices that advertise
that they require PMF but do not support it.  This
is self-inconsistent, but has been seen on a
particular WLAN device acting as a station, so we
accommodate it.

Change-Id: Ic37a5a951bfc536a4bf4a20bb4280789cacfb651
CRs-Fixed: 554610