default or selected kernelversion does not have config value CONFIG_B53_MMAP_DRIVER.
Result is shown for kernelversion 6.0-rc7

B53 MMAP connected switch driver

modulename: b53_mmap.ko
configname: CONFIG_B53_MMAP_DRIVER

Linux Kernel Configuration
└─> Device Drivers
└─> Network device support
└─> Distributed Switch Architecture drivers
└─> Broadcom BCM53xx managed switch support
└─> B53 MMAP connected switch driver

Select to enable support for memory-mapped switches like the BCM63XX
integrated switches.

source code: