default or selected kernelversion does not have config value CONFIG_SERIAL_MPSC.
Result is shown for kernelversion 6.9.9
Marvell MPSC serial port support
modulename: mpsc.ko
configname: CONFIG_SERIAL_MPSC
Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Serial drivers
└─>Marvell MPSC serial port support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)
Say Y here if you want to use the Marvell MPSC serial controller.