CONFIG_LEDS_TIMER is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_LEDS_TIMER.
Result is shown for kernelversion 6.2.5

Timer LED

configname: CONFIG_LEDS_TIMER

Linux Kernel Configuration
└─>Kernel Features
└─>Timer LED
In linux kernel since version 2.6.12  
If you say Y here, one of the system LEDs (the green one on the
NetWinder, the amber one on the EBSA285, or the red one on the LART)
will flash regularly to indicate that the system is still
operational. This is mainly useful to kernel hackers who are
debugging unstable kernels.

The LART uses the same LED for both Timer LED and CPU usage LED
functions. You may choose to use both, but the Timer LED function
will overrule the CPU usage LED.