wireless: remove duplicate enum ieee80211_eid definitions

WLAN_EID_WPA and WLAN_EID_GENERIC mapped to the same value
as WLAN_EID_VENDOR_SPECIFIC. The last one being more in line
with the standard specification. Removing WLAN_EID_WPA and
WLAN_EID_GENERIC as there are no longer drivers using these.

Cc: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>