Remove old style global softconnect

The old softconnect was not flexible enough and has been superceded anyway
with the dynamic softconnect in the mode definition.

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
Update the documentation

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
Update android diag config as diag_mdm port is not usually used + type in softconnect info

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>