CONFIG_XTENSA is not available for thedefaultarchitecture x86.
Result is shown for architecture xtensa

CONFIG_XTENSA (not configurable)

modulename: irq-xtensa-pic.ko

configname: CONFIG_XTENSA

Linux/Xtensa Kernel Configuration
└─>XTENSA
In linux kernel since version 2.6.13 (release Date: 2005-08-28)  
Xtensa processors are 32-bit RISC machines designed by Tensilica
primarily for embedded systems. These processors are both
configurable and extensible. The Linux port to the Xtensa
architecture supports all processor configurations and extensions,
with reasonable minimum requirements. The Xtensa Linux project has
a home page at <http://xtensa.sourceforge.net/>.

selects

CONFIG_ARCH_WANT_FRAME_POINTERS
CONFIG_HAVE_IDE
CONFIG_GENERIC_ATOMIC64
CONFIG_GENERIC_CLOCKEVENTS
CONFIG_VIRT_TO_BUS
CONFIG_GENERIC_IRQ_SHOW
CONFIG_GENERIC_SCHED_CLOCK
CONFIG_MODULES_USE_ELF_RELA
CONFIG_GENERIC_PCI_IOMAP
CONFIG_ARCH_WANT_IPC_PARSE_VERSION
CONFIG_ARCH_WANT_OPTIONAL_GPIOLIB
CONFIG_BUILDTIME_EXTABLE_SORT
CONFIG_CLONE_BACKWARDS
CONFIG_IRQ_DOMAIN
CONFIG_HAVE_OPROFILE
CONFIG_HAVE_FUNCTION_TRACER
CONFIG_HAVE_IRQ_TIME_ACCOUNTING
CONFIG_HAVE_PERF_EVENTS
CONFIG_COMMON_CLK
CONFIG_ARCH_HAS_SG_CHAIN
CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU
CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE
CONFIG_ARCH_NO_COHERENT_DMA_MMAP
CONFIG_DMA_NONCOHERENT_OPS
CONFIG_GENERIC_STRNCPY_FROM_USER
CONFIG_HAVE_ARCH_KASAN
CONFIG_HAVE_DEBUG_KMEMLEAK
CONFIG_HAVE_DMA_CONTIGUOUS
CONFIG_HAVE_EXIT_THREAD
CONFIG_HAVE_FUTEX_CMPXCHG
CONFIG_HAVE_HW_BREAKPOINT
CONFIG_HAVE_MEMBLOCK
CONFIG_HAVE_STACKPROTECTOR
CONFIG_NO_BOOTMEM
CONFIG_PERF_USE_VMALLOC
CONFIG_ARCH_32BIT_OFF_T
CONFIG_ARCH_HAS_BINFMT_FLAT
CONFIG_ARCH_HAS_CURRENT_STACK_POINTER
CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE
CONFIG_ARCH_HAS_DMA_PREP_COHERENT
CONFIG_ARCH_HAS_DMA_SET_UNCACHED
CONFIG_ARCH_HAS_STRNCPY_FROM_USER
CONFIG_ARCH_HAS_STRNLEN_USER
CONFIG_ARCH_USE_MEMTEST
CONFIG_ARCH_USE_QUEUED_RWLOCKS
CONFIG_ARCH_USE_QUEUED_SPINLOCKS
CONFIG_BUILDTIME_TABLE_SORT
CONFIG_DMA_NONCOHERENT_MMAP
CONFIG_GENERIC_LIB_CMPDI2
CONFIG_GENERIC_LIB_MULDI3
CONFIG_GENERIC_LIB_UCMPDI2
CONFIG_HAVE_ARCH_AUDITSYSCALL
CONFIG_HAVE_ARCH_JUMP_LABEL
CONFIG_HAVE_ARCH_KCSAN
CONFIG_HAVE_ARCH_SECCOMP_FILTER
CONFIG_HAVE_ARCH_TRACEHOOK
CONFIG_HAVE_CONTEXT_TRACKING
CONFIG_HAVE_GCC_PLUGINS
CONFIG_HAVE_PCI
CONFIG_HAVE_SYSCALL_TRACEPOINTS
CONFIG_HAVE_VIRT_CPU_ACCOUNTING_GEN
CONFIG_TRACE_IRQFLAGS_SUPPORT
CONFIG_DMA_REMAP

is selected by
CONFIG_SMC91X