This renames all the Tegra20 pinmux pins and functions so they have a
prefix which matches the type name.

The entries in tegra20_pingroups[] are all updated to remove the columns
which are no longer used.

All affected code is updated to match.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NTom Warren <twarren@nvidia.com>