MFC 304018: Add defines needed to export SMBIOS serial numbers

Some defines needed for exporting serial numbers from the SMBIOS were
missed during integration of SMBIOS support in the EFI boot loader (r281138).
This is needed for getting the hostid set from the system hardware UUID.

PR: 206031

MFC r296769: boot/efi: Prefer nm to objdump

Both objdump and nm are equally capable of reporting undefined symbols.

This gets us a step closer to building without binutils as we have an nm
implementation from ELF Tool Chain.

Sponsored by: The FreeBSD Foundation

MFC: r292563

loader.efi: strip trailing whitespace

MFC: r293244 (remainder missing in r294275)

Introduce and use new EFI_ERROR_CODE macro for EFI errors

MFC r294068, r294265

MFC r294068:
Add EFI ZFS boot support

MFC r294265:
Fix broken DPRINTF and wire up EFI_DEBUG so -DEFI_DEBUG to make works.

Relnotes: Yes
Sponsored by: Multiplay

MFC r281169, r293724, r293796, r294029, r294041, r294058

MFC r281169 (by andrew):
Make global variabled only used in this file static

MFC r294058:
Make common boot file_loadraw name parameter const

MFC r294041:
Remove unused reg param from fdt_fixup_memory

MFC r293724:
Enable warnings in EFI boot code

MFC r293796:
Fix typo in libefi.c

MFC r294029:
Only build EFI components on supported compilers

Sponsored by: Multiplay

MFC r287930: Various small cleanups to EFI loader Makefiles.

MFC r281524 by andrew@: Use MACHINE in the efi loader when it is what we mean

It may not be the same as MACHINE_CPUARCH, it just happened to be the
case the architectures this code currently supports.

Fixes build failure reported by Oliver Pinter.

MFC r281138: SMBIOS support for EFI

Restore smbios support lost in r293297

MFC r280950: Move the efi loaders to be under sys/boot/efi

In HEAD this was done to support UEFI on arm64. Merging to stable/10 to
facilitate the merging of later UEFI changes.