dt-bindings: gpio: Remove FSI domain ports on Tegra234

Ports S, T, U and V are in a separate controller that is part of the FSI
domain. Remove their definitions from the MAIN controller definitions to
get rid of the confusion.

This technically breaks ABI compatibility with old device trees. However
it doesn't cause issues in practice. The GPIO pins impacted by this are
used for non-critical functionality.

Fixes: a8b10f3d ("dt-bindings: gpio: Add Tegra234 support")
Signed-off-by: Prathamesh Shete <pshete@nvidia.com>
[treding@nvidia.com: rewrite commit message]
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>