CONFIG_ARCH_MEDIATEK is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
Mediatek MT65xx & MT81xx SoC
modulename: irq-mtk-sysirq.ko
configname: CONFIG_ARCH_MEDIATEK
Linux Kernel Configuration
└─>Mediatek MT65xx & MT81xx SoC
In linux kernel since version 3.10 (release Date: 2013-06-30)
Support for Mediatek MT65xx & MT81xx SoCs