Enable EFI stub support
Run 'make linux-menuconfig'make linux-menuconfig and edit:
Processor type and features --->
Processor type and features ---> [*] EFI runtime service support [*] EFI stub support [?] EFI mixed-mode support EFI mixed-mode support is enabled by default in the kernel settings. https://wiki.gentoo.org/wiki/EFI_Stub