dt-bindings: arm: rockchip: pmu: add rockchip,rk3128-pmu

Add rockchip,rk3128-pmu compatible string.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/faf2b30e-1a1a-0dc1-04ce-f40e5d758718@gmail.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>