drm/meson: overlay: setup overlay for Amlogic FBC Scatter Memory layout

Setup the Amlogic FBC decoder for the VD1 video overlay plane to use
read the FBC header as Scatter Memory layout reference.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200703080728.25207-6-narmstrong@baylibre.com