CONFIG_MACH_REALVIEW_PB11MP is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Support RealView(R) Platform Baseboard for ARM11MPCore

modulename: realview_pb11mp.ko

configname: CONFIG_MACH_REALVIEW_PB11MP

Linux Kernel Configuration
└─>RealView platform type
└─>Support RealView(R) Platform Baseboard for ARM11MPCore
In linux kernel since version 2.6.26 (release Date: 2008-07-13)  
Include support for the ARM(R) RealView(R) Platform Baseboard for
the ARM11MPCore. This platform has an on-board ARM11MPCore and has
support for PCI-E and Compact Flash.

source code:
arch/arm/mach-realview/realview_pb11mp.c