hostapd: recognize 8021x as an authentication mode

Currently, in order to configure the authentication daemon in
8021x mode, we need to set wireless.@wifi-iface[0].encryption="wpa"
Though it works it confuses folks as 8021x is using WEP
encryption and not WPA. Therefore the terminology itself is
confusing. This change adds 8021x as a recognized string for 8021x
authentication.

Signed-off-by: Mathieu Olivari <mathieu@qca.qualcomm.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>

SVN-Revision: 38339