CONFIG_MACH_W90P910EVB is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_MACH_W90P910EVB.
Result is shown for kernelversion 6.9.9

Nuvoton W90P910 Evaluation Board

modulename: mach-nuc910evb.ko

configname: CONFIG_MACH_W90P910EVB

Linux Kernel Configuration
└─>W90P910 Machines
└─>Nuvoton W90P910 Evaluation Board
In linux kernel since version 2.6.29 (release Date: 2009-03-23)  
Say Y here if you are using the Nuvoton W90P910EVB

source code: