i2c: tegra-bpmp: Enable Tegra BPMP I2C adapter

Enable the Tegra BPMP I2C adapter by default if the Tegra BPMP itself
is enabled. This adapter is used as the I2C interface for the PMIC on
the Tegra186 Jetson-TX2 platform.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>