ARM: tegra: harmony: enable HDMI port

Enable host1x, and the HDMI output. Harmony also has an optional LCD,
and a VGA output. The former isn't enabled due to potential issues with
having multiple outputs enabled. The latter isn't enabled since the
driver doesn't support VGA yet anyway.

Correct DDC I2C frequency to 100KHz.

Based on work by Thierry Reding for TrimSlice.

Signed-off-by: Stephen Warren <swarren@nvidia.com>