refactor(fvp): update RSS driver inteface calls

In order to comply with the previous RSS driver change,
interface calls have been updated.

Change-Id: I0a1f3c6a6f8017468d86903cc0158805c6461c28
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
3 files changed