CONFIG_EFI is not available for the selected architecture x86.
Result is shown for architecture riscv

UEFI runtime support

modulename: efi.ko

and/or

memmap.ko

and/or

capsule.ko

and/or

efi-init.ko

configname: CONFIG_EFI

Linux Kernel Configuration
└─>Boot options
└─>UEFI runtime support
In linux kernel since version 2.6.12 )
This option provides support for runtime services provided
by UEFI firmware (such as non-volatile variables, realtime
clock, and platform reset). A UEFI stub is also provided to
allow the kernel to be booted as an EFI application. This
is only useful on systems that have UEFI firmware.