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

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 for kernels that may run on systems that have
UEFI firmware.
source code:
drivers/firmware/efi/