Add ACPI support for Tegra194 & Tegra243 SoC's. This requires
following modifications to the probe when ACPI boot is used:
 - Initialize soc data.
 - Add nvmem lookups.
 - Register soc device.
 - use devm_clk_get_optional() instead of devm_clk_get() to get
   fuse->clk, as fuse clocks are not required when using ACPI boot.

Also, drop '__init' keyword for tegra_soc_device_register() as this is also
used by tegra_fuse_probe() and use dev_err_probe() wherever applicable.
Signed-off-by: Kartik <kkartik@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>