Set -std=gnu++11

Signed-off-by: falkTX <falktx@falktx.com>

Makefile.base.mk

@@ -184,7 +184,7 @@ CXXFLAGS   += -fvisibility-inlines-hidden
 endif
 
 BUILD_C_FLAGS   = $(BASE_FLAGS) -std=gnu99 $(CFLAGS)
-BUILD_CXX_FLAGS = $(BASE_FLAGS) -std=gnu++0x $(CXXFLAGS)
+BUILD_CXX_FLAGS = $(BASE_FLAGS) -std=gnu++11 $(CXXFLAGS)
 LINK_FLAGS      = $(LINK_OPTS) $(LDFLAGS)
 
 ifneq ($(MACOS),true)