wpa_supplicant: Fix compiling without IEEE8021X_EAPOL

wpa_supplicant: Fix compiling without IEEE8021X_EAPOL

If IEEE8021X_EAPOL is not defined wpa_supplicant will not compile with
following error:

  events.c: In function 'wpa_supplicant_connect':
  events.c:1827:14: warning: implicit declaration of function 'eap_is_wps_pbc_enrollee' [-Wimplicit-function-declaration]
   1827 |         if ((eap_is_wps_pbc_enrollee(&ssid->eap) &&
        |              ^~~~~~~~~~~~~~~~~~~~~~~
  events.c:1827:43: error: 'struct wpa_ssid' has no member named 'eap'
   1827 |         if ((eap_is_wps_pbc_enrollee(&ssid->eap) &&
        |                                           ^~

Add ifdef statements around the calling function to fix the issue.

Signed-off-by: Nick Hainke <vincent@systemli.org>