Set the camera I2C to 100kHz, re-enable mode check

- Configure the device tree to give us a 100kHz clock rate on the
camera's I2C bus, to match the Enterprise behavior. This fixes
autofocus, as well.
- At 100kHz I2C speeds, the unconditional mode switch seems to be no
longer required on every stream start, so re-add it.

Change-Id: I7568a11a7b180cc82b959ecaa3b9f3073a078997
2 files changed