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

This reverts commit 668ebd106860f09f43993517f786a2ddfd0f9ebe.

... because of lots of warnings during boot if Linux isn't started as an EFI
application:

WARNING: CPU: 4 PID: 1 at
/work/Linux/linux-2.6-aarch64/drivers/firmware/dmi_scan.c:591 dmi_matches+0x10c/0x110()
dmi check: not initialized yet.
Modules linked in:
CPU: 4 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc4+ #606
Call trace:
[<ffffffc000087fb0>] dump_backtrace+0x0/0x124
[<ffffffc0000880e4>] show_stack+0x10/0x1c
[<ffffffc0004d58f8>] dump_stack+0x74/0xb8
[<ffffffc0000ab640>] warn_slowpath_common+0x8c/0xb4
[<ffffffc0000ab6b4>] warn_slowpath_fmt+0x4c/0x58
[<ffffffc0003f2d7c>] dmi_matches+0x108/0x110
[<ffffffc0003f2da8>] dmi_check_system+0x24/0x68
[<ffffffc0006974c4>] atkbd_init+0x10/0x34
[<ffffffc0000814ac>] do_one_initcall+0x88/0x1a0
[<ffffffc00067aab4>] kernel_init_freeable+0x148/0x1e8
[<ffffffc0004d2c64>] kernel_init+0x10/0xd4

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>