default or selected kernelversion does not have config value CONFIG_SERIAL_M32R_PLDSIO.
Result is shown for kernelversion 6.7-rc3

M32R SIO I/F on a PLD

configname: CONFIG_SERIAL_M32R_PLDSIO

Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Serial drivers
└─>M32R SIO I/F on a PLD
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
Say Y here if you want to use the M32R serial controller
on a PLD (Programmable Logic Device).

If you use an M3T-M32700UT or an OPSPUT platform,
please say Y.