CONFIG_MACH_SHEEVAPLUG_DT is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_MACH_SHEEVAPLUG_DT.
Result is shown for kernelversion 5.10.117

Marvell (eSATA) SheevaPlug (Flattened Device Tree)

modulename: board-sheevaplug.ko

configname: CONFIG_MACH_SHEEVAPLUG_DT

Linux Kernel Configuration
└─>Marvell Kirkwood Implementations
└─>Marvell (eSATA) SheevaPlug (Flattened Device Tree)
In linux kernel since version 3.11 (release Date: 2013-09-02)  
Say 'Y' here if you want your kernel to support the
Marvell (eSATA) SheevaPlug (Flattened Device Tree).

source code:
arch/arm/mach-kirkwood/board-sheevaplug.c