[POWERPC] 4xx: Add PowerPC 440EP Rev C

This adds the 440EP revision C PVR to the CPU table.  The chip has an
FPU on it, so we also match the logical PVR

Signed-off-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>