arm64: dts: rockchip: fix compatible string rk3328 cru node

The cru node references undocumented compatibles of "rockchip,cru" and also
marks it as syscon.

A general rockchip,cru is way too generic to ever be used anywhere, so
needs to go away, similarly the cru should not be written to from other
places, instead regular clock routines should be used.

Both mainline Linux as well as the vendor-kernel up to their 6.1 branch
only reference the cru via the normal assigned-clocks, clocks and resets
properties and do not get a syscon from the node.

Similarly, there is no syscon access by compatible both in mainline
nor the vendor-kernel up to their 6.1 branch, through either the
rockchip,rk3328-cru nor rockchip,cru compatibles.

So these two really are unused in all publically visible places.

Sidenote: the vendor-kernel does pretty crazy stuff in the camera interface
and tdm driver, where they map the cru separately and set clock muxes and
gates directly. This should of course never reach mainline anyway.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
[update commit message, to explain the unused compatibles]
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240930215001.1999212-3-heiko@sntech.de


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