payloads/external/leanefi: Add missing license

Change-Id: Ib95cb55add23fa172f187cbcb475958767f8a923
Signed-off-by: Maximilian Brune <maximilian.brune@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82905
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/payloads/external/leanefi/Kconfig b/payloads/external/leanefi/Kconfig
index 490cbcc..80ee81d 100644
--- a/payloads/external/leanefi/Kconfig
+++ b/payloads/external/leanefi/Kconfig
@@ -1,3 +1,5 @@
+## SPDX-License-Identifier: GPL-2.0-only
+
 if PAYLOAD_LEANEFI
 
 menu "leanEFI configuration"
diff --git a/payloads/external/leanefi/Kconfig.name b/payloads/external/leanefi/Kconfig.name
index 1524d67..cda46e1 100644
--- a/payloads/external/leanefi/Kconfig.name
+++ b/payloads/external/leanefi/Kconfig.name
@@ -1,3 +1,5 @@
+## SPDX-License-Identifier: GPL-2.0-only
+
 config PAYLOAD_LEANEFI
 	bool "leanefi"
 	depends on ARCH_ARM64
diff --git a/payloads/external/leanefi/Makefile b/payloads/external/leanefi/Makefile
index 62d2cd6..1e59cbb 100644
--- a/payloads/external/leanefi/Makefile
+++ b/payloads/external/leanefi/Makefile
@@ -1,3 +1,4 @@
+## SPDX-License-Identifier: GPL-2.0-only
 
 unexport KCONFIG_AUTOHEADER
 unexport KCONFIG_AUTOCONFIG