Compositor control all the input sub-device (VID, GDP)
and the mixer(s).
It is the main entry point for composition.
Layer interface is used to control the abstracted layers.

Add debug in mixer and GDP.
Signed-off-by: NBenjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: NRob Clark <robdclark@gmail.com>

Video Time Generator drivers are used to synchronize the compositor
and tvout hardware IPs by providing line count, sample count,
synchronization signals (HSYNC, VSYNC) and top and bottom fields
indication.
VTG are used by pair for each data path (main or auxiliary)
one for master and one for slave.
Signed-off-by: NBenjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: NRob Clark <robdclark@gmail.com>