arm64: dts: rockchip: update common rk3399 operating points

The rk3399 has multiple variants with different frequency ratings.
The operating points currently in the kernel stem from the op1 variant
used in Gru ChromeOS devices and may not be suitable for general rk3399
chips. Therefore bring it back to the official general operating points.

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