arm64: dts: stratix10: use clock bindings for the Stratix10 platform

Use the clock bindings for the Stratix10 SoC. This includes changing the old
binding of "intc,clk-s10-mgr" to "intel,stratix10-clkmgr". The reason that
this can be done is that there are currently no clock driver for Stratix10,
thus there are no consumers of the old binding. So changing the binding will
not break any legacy code.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
---
v7:
- move PLL out of clkmgr node and into DT root
v6:
- no changes
v5:
- no changes
v4:
- remove '_' in name of clock nodes
- use clock-controller in SoCDK node in dts file
v3:
- use the correct vendor prefix
- explain the binding change
v2:
- use a single clock binding for the clock controller