CONFIG_PCI_IRQ_LEVEL is not available for thedefaultarchitecture x86.
Result is shown for architecture mn10300
default or selected kernelversion does not have config value CONFIG_PCI_IRQ_LEVEL.
Result is shown for kernelversion 6.7-rc3

PCI interrupt priority

configname: CONFIG_PCI_IRQ_LEVEL

Linux Kernel Configuration
└─>Panasonic MN10300 system setup
└─>Interrupt request priority options
└─>PCI interrupt priority
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
depends
CONFIG_PCI