powerpc/mpc85xx: Use IFC accessor function

IFC registers can be of type Little Endian or big Endian depending upon
Freescale SoC. Here SoC defines the register type of IFC IP.

So use IFC acessor functions instead of in_be32().

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>