treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

efi: Add efi_test driver for exporting UEFI runtime service interfaces

This driver is used by the Firmware Test Suite (FWTS) for testing the UEFI
runtime interfaces readiness of the firmware.

This driver exports UEFI runtime service interfaces into userspace,
which allows to use and test UEFI runtime services provided by the
firmware.

This driver uses the efi.<service> function pointers directly instead of
going through the efivar API to allow for direct testing of the UEFI
runtime service interfaces provided by the firmware.

Details for FWTS are available from,
<https://wiki.ubuntu.com/FirmwareTestSuite>

Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
Cc: joeyli <jlee@suse.com>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>