CONFIG_ARCH_MVEBU is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

Marvell EBU SoC Family

configname: CONFIG_ARCH_MVEBU

Linux Kernel Configuration
└─>Platform selection
└─>Marvell EBU SoC Family
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This enables support for Marvell EBU familly, including:
- Armada 3700 SoC Family
- Armada 7K SoC Family
- Armada 8K SoC Family
- 98DX2530 SoC Family