Modify OpenAL-soft Android.mk

The comment is self-explanatory.

love/src/jni/openal-soft-1.18.2/Android.mk

@@ -8,6 +8,11 @@ LOCAL_CFLAGS    := -DAL_ALEXT_PROTOTYPES -DAL_BUILD_LIBRARY -D_GNU_SOURCE=1 -D_P
 
 LOCAL_CPPFLAGS  := ${LOCAL_CFLAGS}
 
+ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
+	# ARM64 have log2f function
+	LOCAL_CFLAGS += -DHAVE_LOG2F
+endif
+
 LOCAL_C_INCLUDES  :=  \
 	${LOCAL_PATH}/include \
 	${LOCAL_PATH}/common \