package/edid-decode: overwrite warning flags (fixes gcc-4.8 compile)

Overwrite default compiler warning flags to fix gcc-4.8 compile.

Fixes:

  http://autobuild.buildroot.net/results/fff2cadaee1fa8c028ac558e852f7e52b1c8317b

  .../bin/arm-none-linux-gnueabi-g++ -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -Os -g0 -D_FORTIFY_SOURCE=1 -std=c++11  -Wall -Wextra -Wno-missing-field-initializers -Wno-unused-parameter -Wimplicit-fallthrough -g -DSHA= -DDATE= -o edid-decode.o -c edid-decode.cpp
  arm-none-linux-gnueabi-g++: error: unrecognized command line option '-Wimplicit-fallthrough'

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/edid-decode/edid-decode.mk

@@ -12,7 +12,7 @@ EDID_DECODE_LICENSE_FILES = LICENSE
 
 define EDID_DECODE_BUILD_CMDS
 	$(TARGET_MAKE_ENV) $(TARGET_CONFIGURE_OPTS) $(MAKE) -C $(@D) \
-		CFLAGS="$(TARGET_CXXFLAGS) -std=c++11"
+		CFLAGS="$(TARGET_CXXFLAGS) -std=c++11" WARN_FLAGS=
 endef
 
 define EDID_DECODE_INSTALL_TARGET_CMDS