Add documentation for the Rockchip RK3568 Video Capture (VICAP) unit.
Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> Signed-off-by: Michael Riesch <michael.riesch@collabora.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>