media: dt-bindings: rockchip,vdec: Add RK3288 compatible

media: dt-bindings: rockchip,vdec: Add RK3288 compatible

Add a RK3288 compatible for a version of the Rockchip VDEC IP that only
support HEVC decoding.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Diederik de Haas <didi.debian@cknow.org>  # Rock64, RockPro64, Quartz64-B, NanoPi R5S
Tested-by: Detlev Casanova <detlev.casanova@collabora.com> # RK3399
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>