tegra: i2c: Add function to find DVC bus

Add tegra_i2c_get_dvc_bus_num() to obtain the I2C bus number of DVC bus.
This allows us to talk to the PMU.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
2 files changed