CONFIG_CPU_PXA300 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
CONFIG_CPU_PXA300 (not configurable)
modulename: pxa300.ko
configname: CONFIG_CPU_PXA300
Linux Kernel Configuration
└─>CPU_PXA300
In linux kernel since version 2.6.24 (release Date: 2008-01-24)
PXA300 (codename Monahans-L)