ARM: tegra: Tegra20 pinmux cleanup

ARM: tegra: Tegra20 pinmux cleanup

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: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>