default or selected kernelversion does not have config value CONFIG_PWM_XILINX.
Result is shown for kernelversion 6.9-rc5

Xilinx AXI Timer PWM support

modulename: pwm-xilinx.ko

configname: CONFIG_PWM_XILINX

Linux Kernel Configuration
└─>Device Drivers
└─>Pulse-Width Modulation (PWM) Support
└─>Common Clock Framework
└─>Xilinx AXI Timer PWM support
In linux kernel since version 5.2 (release Date: 2019-07-07)  
PWM driver for Xilinx LogiCORE IP AXI timers. This timer is
typically a soft core which may be present in Xilinx FPGAs.
This device may also be present in Microblaze soft processors.
If you don't have this IP in your design, choose N.

To compile this driver as a module, choose M here: the module
will be called pwm-xilinx.

source code: