arm64: dts: rockchip: add gpu node to rk356x

arm64: dts: rockchip: add gpu node to rk356x

Rockchip SoCs RK3566 and RK3568 have a Mali Gondul core
which is based on the Bifrost architecture. It has
one shader core and two execution engines.

Quoting the datasheet:

Mali-G52 1-Core-2EE
* Support 1600Mpix/s fill rate when 800MHz clock frequency
* Support 38.4GLOPs when 800MHz clock frequency

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Alex Bee <knaerzche@gmail.com>
Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
Link: https://lore.kernel.org/r/20220209215549.94524-3-michael.riesch@wolfvision.net
Signed-off-by: Heiko Stuebner <heiko@sntech.de>