CONFIG_IRQ_MV64340 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_IRQ_MV64340 (not configurable)

modulename: irq-mv6434x.ko

configname: CONFIG_IRQ_MV64340

Linux/MIPS Kernel Configuration
└─>Machine selection
└─>IRQ_MV64340
In linux kernel since version 2.6.12  
source code:
arch/mips/kernel/irq-mv6434x.c