Add I/O pad table for Tegra234 to allow configuring DPD mode and
switching the pins to 1.8V or 3.3V as needed.
On Tegra234, DPD registers are reorganized such that there is a DPD_REQ
register and a DPD_STATUS register per pad group. Update the PMC driver
accordingly.
While at it, use the generated tables from tegra-pinmux-scripts to make
the formatting of these tables more consistent.