gpio: tegra186: Add ACPI support

Add ACPI module ID to probe the driver from the ACPI based bootloader
firmware.

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>