Previously, nonzero sae_h2e parameter values were used to perform SAE
H2E specific operations (deriving PT, adding RSNXE, adding H2E-only BSS
membership selector) in AP mode even if SAE was not enabled for the
network. This could result in unexpected behavior if sae_pwe=1 or
sae_pwe=2 were set in the configuration. Fix this by making the SAE
operations conditional on SAE being actually enabled.
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>