media: dt-bindings: amlogic,meson-gx-ao-cec: move to cec subfolder

Move amlogic,meson-gx-ao-cec.yaml bindings to cec subfolder and drop
unneeded quotes.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>