i2c: tegra: Set ACPI node as primary fwnode

Set ACPI node as the primary fwnode of I2C adapter to allow
enumeration of child devices from the ACPI table

Signed-off-by: Zubair Waheed <zwaheed@nvidia.com>
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>