drm: sti: add VID layer

VIDeo plug are one of the compositor input sub-devices.
VID are dedicated to video inputs like YUV plans.

Like GDP, VID are part of Compositor hardware block
and use sti_layer structure to provide an abstraction for
Compositor calls.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/sti/Makefile b/drivers/gpu/drm/sti/Makefile
index 7de757f..9b613d2 100644
--- a/drivers/gpu/drm/sti/Makefile
+++ b/drivers/gpu/drm/sti/Makefile
@@ -1,5 +1,6 @@
 sticompositor-y := \
-	sti_gdp.o
+	sti_gdp.o \
+	sti_vid.o
 
 stihdmi-y := sti_hdmi.o \
 	sti_hdmi_tx3g0c55phy.o \