efi: x86: Set the NX-compatibility flag in the PE header
Following Baskov Evgeniy's "Handle UEFI NX-restricted page tables" patches, it's safe to set this compatibility flag to let loaders know they don't need to make special accommodations for kernel to load if pre-boot NX is enabled.
This MR includes the "Handle UEFI NX-restricted page tables" patches as well as the patch to actually set the flag in the header. They are queued for the 5.19 merge window [1], but will be needed in 5.18 for a shim build.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/efi/efi.git/log/