CONFIG_CPU_ARM720T is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Support ARM720T processor

modulename: proc-arm720.ko

configname: CONFIG_CPU_ARM720T

Linux Kernel Configuration
└─>Support ARM720T processor
In linux kernel since version 2.6.12  
A 32-bit RISC processor with 8kByte Cache, Write Buffer and
MMU built around an ARM7TDMI core.

Say Y if you want support for the ARM720T processor.
Otherwise, say N.

source code: