misc: lan966x_pci: Fix dtc warns 'missing or empty reg/ranges property'

misc: lan966x_pci: Fix dtc warns 'missing or empty reg/ranges property'

dtc generates the following warnings when building the LAN966x device
tree overlay (lan966x_pci.dtso):
  Warning (simple_bus_reg): /fragment@0/__overlay__/pci-ep-bus@0/cpu_clk: missing or empty reg/ranges property
  Warning (simple_bus_reg): /fragment@0/__overlay__/pci-ep-bus@0/ddr_clk: missing or empty reg/ranges property
  Warning (simple_bus_reg): /fragment@0/__overlay__/pci-ep-bus@0/sys_clk: missing or empty reg/ranges property

Indeed, related nodes are under the pci-ep-bus (simple-bus) which is not
correct.

Put them outside this node.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/all/20241025110919.64b1cffb@canb.auug.org.au/
Fixes: 185686beb464 ("misc: Add support for LAN966x PCI device")
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20241029084338.194942-2-herve.codina@bootlin.com
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>