SAE: A bit optimized sae_confirm_immediate=2 for testing purposes

SAE: A bit optimized sae_confirm_immediate=2 for testing purposes

sae_confirm_immediate=2 can now be used in CONFIG_TESTING_OPTIONS=y
builds to minimize the latency between SAE Commit and SAE Confirm by
postponing transmission of SAE Commit until the SAE Confirm frame is
generated. This does not have significant impact, but can get the frames
tiny bit closer to each other over the air to increase testing coverage.
The only difference between sae_confirm_immediate 1 and 2 is in the
former deriving KCK, PMK, PMKID, and CN between transmission of the
frames (i.e., a small number of hash operations).

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