Do not clear PMKSA entry or EAP session cache if config does not change

Do not clear PMKSA entry or EAP session cache if config does not change

This avoids unnecessary flushing of the PMKSA cache entry and EAP
session data when processing SET_NETWORK commands that set a network
profile parameter to the same value that the parameter already has.

Introduce a new wpa_config_set() and wpa_config_set_quoted() return
value (==1) signifying that the new value being set for the
corresponding field equals to the already configured one so that the
caller can determine that nothing changed in the profile.

For now, this does not cover all the network profile parameters, but
number of the most commonly used parameters are included to cover the
Android use cases where the framework may have issued SET_NETWORK
commands that would have unnecessarily prevented use of PMKSA caching or
EAP fast reauthentication.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>