Make v3oidcpassword send client_id

Updates the v3oidcpassword function to also send the client_id as part of the request body,
this seems to be a requirement for services like onelogin.

Change-Id: I2392ef51302804c0c66c0fb52227db5f35bca3fd
(cherry picked from commit 30d61ad316)

keystoneauth1/identity/v3/oidc.py

@@ -326,7 +326,8 @@ class OidcPassword(_OidcBase):
         """
         payload = {'username': self.username,
                    'password': self.password,
-                   'scope': self.scope}
+                   'scope': self.scope,
+                   'client_id': self.client_id}
         return payload