FT: Allow PMK-R0 and PMK-R1 for FT-PSK to be generated locally

FT: Allow PMK-R0 and PMK-R1 for FT-PSK to be generated locally

Station should be able to connect initially without ft_pmk_cache filled,
so the target AP has the PSK available and thus the same information as
the origin AP. Therefore neither caching nor communication between the
APs with respect to PMK-R0 or PMK-R1 or VLANs is required if the target
AP derives the required PMKs locally.

This patch introduces the generation of the required PMKs locally for
FT-PSK. Additionally, PMK-R0 is not stored (and thus pushed) for FT-PSK.

So for FT-PSK networks, no configuration of inter-AP communication is
needed anymore when using ft_psk_generate_local=1 configuration. The
default behavior (ft_psk_generate_local=0) remains to use the pull/push
protocol.

Signed-off-by: Michael Braun <michael-dev@fami-braun.de>