RSN: Do not allow connection to proceed without MFPC=1 if PMF required

RSN: Do not allow connection to proceed without MFPC=1 if PMF required

PMF capability check is done as part of BSS selection routines, but
those are not used when going through the enforced roaming operation
("ROAM <BSSID>" control interface command). While that mechanism is
mainly for testing purposes, extend it to do the same check for PMF to
prevent cases where forced roaming could end up disabling PMF against
the local profile requirement.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>