package/flatbuffers: enable host build

Host version of flatc compiler is needed for Kodi 18.x:
https://github.com/xbmc/xbmc/blob/master/cmake/modules/FindFlatBuffers.cmake#L51

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/flatbuffers/flatbuffers.mk

@@ -20,4 +20,14 @@ else
 FLATBUFFERS_CONF_OPTS += -DFLATBUFFERS_BUILD_SHAREDLIB=ON
 endif
 
+HOST_FLATBUFFERS_CONF_OPTS += \
+	-DCMAKE_CXX_FLAGS="-std=c++11" \
+	-DFLATBUFFERS_BUILD_FLATLIB=OFF \
+	-DFLATBUFFERS_BUILD_FLATC=ON \
+	-DFLATBUFFERS_BUILD_FLATHASH=OFF \
+	-DFLATBUFFERS_BUILD_GRPCTEST=OFF \
+	-DFLATBUFFERS_BUILD_SHAREDLIB=OFF \
+	-DFLATBUFFERS_BUILD_TESTS=OFF
+
 $(eval $(cmake-package))
+$(eval $(host-cmake-package))