CONFIG_CPU_ARM720T is not available for the default architecture x86.
Result is shown for architecture arm

CONFIG_CPU_ARM720T (not configurable)

modulename: proc-arm720.ko
configname: CONFIG_CPU_ARM720T

Linux Kernel Configuration
└─> CPU_ARM720T

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: