Enable EAP-pwd configuration in WiFi Settings.

EAP-pwd (RFC 5931) is an EAP method that uses a shared password
for authentication. It has the simplicity of setup as WPA2-PSK
(no certificates), but provides strong authenticaiton like 802.1x.

Modified the Settings screen so that the only visible fields
when choosing EAP-pwd are 'identity' and 'password'.

Change-Id: I9365d873b43c416ddfa4cae47b7419d902c212a7
Signed-off-by: Partha N <parthan@gmail.com>