Add support for the new smp_twd runtime registration interface
to the tegra platforms, and remove the old compile-time support.
Tested on Harmony.
Acked-by: Stephen Warren <swarren@nvidia.com> Cc: Colin Cross <ccross@android.com> Cc: Olof Johansson <olof@lixom.net> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>