drm/tegra: sor: Add HDMI support

The SOR1 introduced on Tegra210 supports HDMI 2.0 and DisplayPort. Add
HDMI support and name the debugfs node after the type of SOR. The SOR
introduced with Tegra124 is known simply as "sor", whereas the
additional SOR found on Tegra210 is known as "sor1".

Signed-off-by: Thierry Reding <treding@nvidia.com>