soc/tegra: pmc: Use X macro to generate IO pad tables

Refactor the IO pad tables into macro tables so that they can be reused
to generate pinctrl pin descriptors. Also add a name field which is
needed by pinctrl.

Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>