tegra194-hte.rst: fix reference to its binding

The binding directory for hte was renamed. Update references accordingly.

Fixes: af583852 ("dt-bindings: Renamed hte directory to timestamp")
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Reviewed-by: Dipen Patel <dipenp@nvidia.com>
Link: https://lore.kernel.org/r/2e2c86485cb0642455cee01796f9a74de21403e6.1656234456.git.mchehab@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>