default or selected kernelversion does not have config value CONFIG_ADB_PMU68K.
Result is shown for kernelversion 6.7-rc3

Include PMU (Powerbook) ADB driver

modulename: via-pmu68k.ko

configname: CONFIG_ADB_PMU68K

Linux Kernel Configuration
└─>Device Drivers
└─>Macintosh device drivers
└─>Include PMU (Powerbook) ADB driver
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
Say Y here if want your kernel to support the m68k based Powerbooks.
This includes the PowerBook 140, PowerBook 145, PowerBook 150,
PowerBook 160, PowerBook 165, PowerBook 165c, PowerBook 170,
PowerBook 180, PowerBook, 180c, PowerBook 190cs, PowerBook 520,
PowerBook Duo 210, PowerBook Duo 230, PowerBook Duo 250,
PowerBook Duo 270c, PowerBook Duo 280 and PowerBook Duo 280c.

source code: