CONFIG_PPC_MPC52xx is not available for thedefaultarchitecture x86.
Result is shown for architecture ppc

CONFIG_PPC_MPC52xx (not configurable)

modulename: mpc52xx_setup.ko

configname: CONFIG_PPC_MPC52xx

Linux/PowerPC Kernel Configuration
└─>Platform options
└─>PPC_MPC52xx
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
source code:
arch/ppc/syslib/
is selected by
CONFIG_USB_OHCI_HCD_PCI