board: fsl: lx2160a: implement board_fix_fdt

lx2160a rev1 and rev2 SoC has different pcie controller.
The pcie controller device tree node fields "compatible"
and registers names needs to be updated accordingly

This change in device tree is handled as part of
fdt fixups. These changes would only be applied
if the soc revision is not rev1.

Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>