freeradius3: Enable the EAP-PWD module.

freeradius3: Enable the EAP-PWD module.

This enables the EAP-PWD module, which allows for logging in with only
a username and password, while still being secure (see the links below
for the details of this EAP method, if interested).

https://en.wikipedia.org/wiki/Extensible_Authentication_Protocol#EAP_Password_(EAP-PWD)

Also found this blog post which talks about EAP-PWD and its benefits:
https://dustri.org/b/eap-pwd-wifi-security-done-right.html

Signed-off-by: Robby K <robbyke@gmail.com>