arm64: dts: ls1043a: Add SCFG phandle for PCIe nodes

The LS1043A PCIe controller has some control registers
in SCFG block, so add the SCFG phandle for each PCIe
controller node.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>