dt-bindings: media: amlogic,gx-vdec: add the GXLX SoC family and update GXL

The GXLX SoC is a GXL variant that omits VP9 codec support. Also add S905W
and S905Y as GXL chips and sort the GXL comment.

Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>