vendorcode/eltan: Add vendor code for measured and verified boot

This patch contains the general files for the vendorcode/eltan that has
been uploaded recently:
- Add eltan directory to vendorcode.
- Add documentation about the support in the vendorcode directories.
- Add the Makefile.inc and Kconfig for the vendorcode/eltan and
  vendorcode/eltan/security.

BUG=N/A
TEST=Created verified binary and verify logging on Portwell PQ-M107

Change-Id: Ic1d5a21d40b6a31886777e8e9fe7b28c860f1a80
Signed-off-by: Frans Hendriks <fhendriks@eltan.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/30218
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>

src/vendorcode/Makefile.inc

@@ -3,3 +3,4 @@ subdirs-y += google
 subdirs-y += intel
 subdirs-y += siemens
 subdirs-y += cavium
+subdirs-y += eltan

src/vendorcode/eltan/Kconfig

@@ -0,0 +1,17 @@
+##
+## This file is part of the coreboot project.
+##
+## Copyright (C) 2014-2018 Eltan B.V.
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; version 2 of the License.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+
+source src/vendorcode/eltan/security/mboot/Kconfig
+source src/vendorcode/eltan/security/verified_boot/Kconfig

src/vendorcode/eltan/Makefile.inc

@@ -0,0 +1,16 @@
+#
+# This file is part of the coreboot project.
+#
+# Copyright (C) 2018 Eltan B.V.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+
+subdirs-y += security

src/vendorcode/eltan/security/Kconfig

@@ -0,0 +1,16 @@
+## This file is part of the coreboot project.
+##
+## Copyright (C) 2018 Eltan B.V.
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; version 2 of the License.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+
+source src/vendorcode/eltan/security/mboot/Kconfig
+source src/vendorcode/eltan/security/verified_boot/Kconfig

src/vendorcode/eltan/security/Makefile.inc

@@ -0,0 +1,30 @@
+## This file is part of the coreboot project.
+##
+## Copyright (C) 2018 Eltan B.V.
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; version 2 of the License.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+
+subdirs-y += lib
+subdirs-y += verified_boot
+subdirs-y += mboot
+
+ifeq ($(CONFIG_MBOOT), y)
+CPPFLAGS_common += -I$(src)/vendorcode/eltan/security/mboot
+CPPFLAGS_common += -I$(src)/vendorcode/eltan/security/include
+endif
+
+ifeq ($(CONFIG_VERIFIED_BOOT), y)
+CPPFLAGS_common += -I$(src)/vendorcode/eltan/security/verified_boot
+endif
+
+ifeq ($(CONFIG_TPM2),y)
+CPPFLAGS_common += -I$(src)/security/include
+endif