ARM: tegra: trimslice: enable HDMI port

Enable host1x, and the HDMI output. Harmony also has a DVI port with an
HDMI form-factor connector, driven by Tegra's LVDS output. This isn't
enabled yet, due to potential issues with having multiple outputs enabled.

Correct DDC I2C frequency to 100KHz.

Add dummy/fixed regulators to satisfy the HDMI driver.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
[swarren: add commit description, remove enable of DVI port]
Signed-off-by: Stephen Warren <swarren@nvidia.com>