Revert "arm64: dmi: Add SMBIOS/DMI support"

This reverts commit a28e3f4b.

Ard and Yi Li report that this patch is broken by design, so revert it
and let them sort it out for 3.18 instead.

Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>