powerpc: MPC85xxCDS: Disable legacy PCI fixup when DM_PCI is selected

Disable legacy PCI and PCIe fixup when CONFIG_DM_PCI is selected.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>