Merge pull request #17 from ardera/devel-pi4

Integrate Raspberry Pi 4 Compatibility

Author: ardera

Makefile

@@ -1,6 +1,6 @@
 CC = cc
 LD = cc
-REAL_CFLAGS = -I./include $(shell pkg-config --cflags dri gbm libdrm glesv2 egl) -D_GNU_SOURCE -DBUILD_ELM327PLUGIN $(CFLAGS)
+REAL_CFLAGS = -I./include $(shell pkg-config --cflags dri gbm libdrm glesv2 egl) -DBUILD_ELM327PLUGIN $(CFLAGS)
 REAL_LDFLAGS = $(shell pkg-config --libs dri gbm libdrm glesv2 egl) -lrt -lflutter_engine -lpthread -ldl $(LDFLAGS)
 
 SOURCES = src/flutter-pi.c src/platformchannel.c src/pluginregistry.c src/plugins/elm327plugin.c src/plugins/services-plugin.c src/plugins/testplugin.c