arm64: tegra: Simplify Tegra210 GPIO compatible value

The compatible value need only include an entry for the specific HW
generation, plus the oldest HW version that introduced changes it is
backwards-compatible with; intermediate versions aren't necessary. Since
Tegra124 GPIO is backwards-compatible with Tegra30 GPIO, there's no need
to include the Tegra124 value in the Tegra210 DTS. This makes the kernel
DT better match the copy of the DT files included in U-Boot.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>