arm: dts: rockchip: rk3566: Remove unnecessary clks from rgxx3

Remove unnecessary clock frequency defines from the RGxx3 u-boot dts.
Move the necessary defines to the RGxx3 main dts file.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>