ARM64 WIP: Fake PE header assembly

Can probably be done cleaner, but at least UEFI boots it atm

system/boot: Unify spin design, add missing symbols to asm/ld

Change-Id: I1dd98a2243d498ec1c827f7a60385237d12a0d39
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2283
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

efi: Refactor our EFI code to use fuchsia's cleaner EFI headers.

* Drop gnu-efi

Change-Id: Ib601fc8ced49b18281b6b98cf861a5aef1b9c065
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2026
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>