[PATCH] kbuild: Add DTC_CPP_FLAGS

[Frank Wunderlich]

With this Patch we are able to change cpp-preprocessor options
(e.g. -D...) for using conditions (#ifdef) in devicetree files
and dynamically add include searchpaths

Signed-off-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx>
---
 scripts/Makefile.lib | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 3fa32f83b2d7..c722a6c7786a 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -177,7 +177,7 @@ DTC_INCLUDE    := $(srctree)/scripts/dtc/include-prefixes
 
 dtc_cpp_flags  = -Wp,-MD,$(depfile).pre.tmp -nostdinc                    \
 		 $(addprefix -I,$(DTC_INCLUDE))                          \
-		 -undef -D__DTS__
+		 -undef -D__DTS__ $(DTC_CPP_FLAGS)
 
 # Useful for describing the dependency of composite objects
 # Usage:
-- 
2.17.1