CONFIG_MACH_MMP3_DT is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Support MMP3 (ARMv7) platforms

modulename: platsmp.ko

and/or

mmp3.ko

configname: CONFIG_MACH_MMP3_DT

Linux Kernel Configuration
└─>Marvell PXA168/910/MMP2/MMP3
└─>Marvell PXA168/910/MMP2 Implementations
└─>Support MMP3 (ARMv7) platforms
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
Say 'Y' here if you want to include support for platforms
with Marvell MMP3 processor, also known as PXA2128 or
Armada 620.

source code:
arch/arm/mach-mmp/platsmp.c