mb/clevo/cml-u: Use include folder for header files

Change-Id: I50be3d9b829f624cbe460060c40482047f39774c
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47833
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>
diff --git a/src/mainboard/clevo/cml-u/Makefile.inc b/src/mainboard/clevo/cml-u/Makefile.inc
index 1d9ed2d..3af82dd 100644
--- a/src/mainboard/clevo/cml-u/Makefile.inc
+++ b/src/mainboard/clevo/cml-u/Makefile.inc
@@ -1,2 +1,4 @@
+CPPFLAGS_common += -I$(src)/mainboard/$(MAINBOARDDIR)/variants/$(VARIANT_DIR)/include
+
 ramstage-y += variants/$(VARIANT_DIR)/hda_verb.c
 subdirs-y += variants/$(VARIANT_DIR)
diff --git a/src/mainboard/clevo/cml-u/variants/l140cu/bootblock.c b/src/mainboard/clevo/cml-u/variants/l140cu/bootblock.c
index 2b67302..427b023 100644
--- a/src/mainboard/clevo/cml-u/variants/l140cu/bootblock.c
+++ b/src/mainboard/clevo/cml-u/variants/l140cu/bootblock.c
@@ -2,7 +2,7 @@
 
 #include <bootblock_common.h>
 #include <gpio.h>
-#include "gpio.h"
+#include <variant/gpio.h>
 
 void bootblock_mainboard_init(void)
 {
diff --git a/src/mainboard/clevo/cml-u/variants/l140cu/gpio.h b/src/mainboard/clevo/cml-u/variants/l140cu/include/variant/gpio.h
similarity index 100%
rename from src/mainboard/clevo/cml-u/variants/l140cu/gpio.h
rename to src/mainboard/clevo/cml-u/variants/l140cu/include/variant/gpio.h
diff --git a/src/mainboard/clevo/cml-u/variants/l140cu/ramstage.c b/src/mainboard/clevo/cml-u/variants/l140cu/ramstage.c
index 46651e8..037409c 100644
--- a/src/mainboard/clevo/cml-u/variants/l140cu/ramstage.c
+++ b/src/mainboard/clevo/cml-u/variants/l140cu/ramstage.c
@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <soc/ramstage.h>
-#include "gpio.h"
+#include <variant/gpio.h>
 
 void mainboard_silicon_init_params(FSP_S_CONFIG *params)
 {